During the Cold War, both superpowers, the U.S., and the USSR, built massive nuclear arsenals, aimed, to a large extent, at each other. However, they were never used, as after a time, leaders on both sides of the Iron Curtain realized that global thermonuclear war would not be in either power's national interest, as it would probably lead to the destruction of both nations, and possibly nuclear winter or other extinction level events. Therefore, at times, both sides refrained from deploying systems capable of unanswerable nuclear strikes against either side. However, in both nations, there were interests that benefited from the development and maintenance of first-strike weapons systems—what Dwight Eisenhower termed the military-industrial complex; these forces encouraged the constant development of weapons systems of greater accuracy, power, and destruction. In addition, each side doubted the other side's commitment to not deploy first-strike weapons, or even in the event of their deployment, to not strike first. Some first-strike weapons were deployed; however, they were never used.
Of the nuclear powers, only the People's Republic of China and the Republic of India have declarative, unqualified, unconditional no-first-use policies. In 1982, at a special session of General Assembly of United Nations, the USSR pledged not to use nuclear weapons first, regardless of whether its opponents possessed nuclear weapons or not. This pledge was later abandoned by post-Soviet Russia. The United States has a partial, qualified no-first-use policy, stating that they will not use nuclear weapons against states without nuclear weapons or other weapons of mass destruction.
Large scale missile defense systems are not first-strike weapons, however, critics view them as first-strike enabling weapons. Ronald Reagan's proposed Strategic Defense Initiative, if it had ever been deployed (and proven successful), would have undermined the fundamental premise of mutual assured destruction (the inevitable outcome of equal and unacceptable destruction for both sides in the event of nuclear war), removing the incentive for the U.S. not to strike first. These proposed defense systems, intended to lessen the risk of devastating nuclear war, would lead to it, according to critics. Indeed, according to game theory, the side not building a large-scale missile defense, seeing that a nation was building a defense against a first strike and believing that the other could launch a first strike if it dared, would then launch a pre-emptive first strike while they were still assured that such a strike would get through.
First-strike attack, the use of a nuclear first strike capability, was greatly feared during the Cold War between the United States and the Soviet Union. At various points, fear of a first strike attack existed on both sides. Misunderstood changes in posture and well understood changes in technology used by either side were usually fuel on the fire of speculation regarding the enemy's intentions.
In the immediate aftermath of the Great Patriotic War, the Soviet Union feared the United States would use its nuclear superiority to devastate the Socialist Motherland, as from 1945-1948, the U.S. was the only state possessing nuclear weapons. The USSR countered by rapid development of their own nuclear weapons, with a test first occurring in 1949., and the U.S. was taken by surprise. In turn, the U.S. countered by developing the vastly more powerful thermonuclear weapon, testing their first hydrogen bomb in 1952 at Ivy Mike, but the USSR quickly countered by testing their own thermonuclear weapons, with a test in 1953 of a semi-thermonuclear weapon of the Sloika design, and in 1956, with the testing of Sakharov's Third Idea - equivalent to the Castle Bravo device. Meanwhile, tensions between the two nations rose as 1956 saw the brutal suppression of Hungary by the Red Army; the U.S. and European nations drew certain obvious and inevitable conclusions from that event, while in the U.S., full scale hysteria was afoot, prompted by Joseph McCarthy, HUAC, and Julius and Ethel Rosenberg, two atomic spies. This atmosphere was further inflamed by the 1957 launch of Sputnik, which led to wild fears of Communists attacking from space, as well as very real fears about the fact that if the Soviets could launch something over one's head, they could launch something else that could hit one's head. John F. Kennedy capitalized on this situation by emphasizing the Bomber Gap and the Missile Gap, areas which the Soviets were (inaccurately) perceived as leading the United States in, while heated Soviet rhetoric, including Nikita Khruschev's famous threat that "We will bury you!" to Western ambassadors didn't help to cool tensions. The 1960 U-2 incident, involving Francis Gary Powers, as well as the Berlin Crisis, along with the test of the Tzar Bomba, escalated tensions to unheard of levels.
This escalating situation came to a head with the Cuban Missile Crisis of 1962. The arrival of Soviet missiles in Cuba was conducted by the Soviets on the basis that the US already had nuclear missiles stationed in Turkey, as well as the desire by Fidel Castro to increase his power, his freedom of action, and to protect his government from US-initiated prejudicial resolution of ideological disputes through the use of military force, such as had been attempted at the Bay of Pigs during the previous year. During the crisis, Fidel Castro wrote Khrushchev a letter about the prospect that the "imperialists" would be "extremely dangerous" if they responded militarily to the Soviet stationing of nuclear missiles aimed at US territory, less than 90 miles away from Cuba. The following quotation from the letter suggests that Castro was calling for a Soviet first strike against the US if it responded militarily to the placement of nuclear missiles in Cuba:
Luckily, rational minds prevailed. The Cuban Missile Crisis resulted in Khrushchev publicly agreeing to remove the missiles from Cuba, while Kennedy secretly agreed to remove the missiles from Turkey. Both sides in the Cold War realized how close they came to nuclear war over Cuba, and decided to seek a reduction of tensions, resulting in US-Soviet détente for most of the 1960s and 1970s.
However, tensions were inflamed again in the late 1970s and early 1980s, with the Soviet invasion of Afghanistan, and the decision of NATO to deploy the new Pershing II IRBM as well as the Tomahawk Ground-Launched Cruise Missile, along with Ronald Reagan's talk of 'limited' nuclear war. This increased Soviet fears that NATO was planning an attack. NATO's deployment of these missiles was a response to the Soviet deployment of the SS-20 Pioneer, which could hit most European NATO bases within minutes of launch. These mutual deployments led to a destabilizing strategic situation, which was exacerbated by malfunctioning U.S. and Soviet missile launch early warning systems, a Soviet intelligence gap that prevented the Soviets from getting a "read" on the strategic intentions of U.S. leaders, as well as overheated U.S. rightist rhetoric combined with classical Soviet paranoia. This culminated in a war scare that occurred during 1983 due to the inopportune timing of a NATO exercise called Able Archer, which was a simulation of a NATO nuclear attack on the Soviet Union; this exercise happened to occur during a massive Soviet intelligence mobilization called VRYAN, that was designed to discover intentions of NATO to initiate a nuclear first-strike. This poor timing drove the world very close to nuclear war, possibly even closer than the Cuban Missile Crisis over 20 years before.
But rational minds once again prevailed, and both sides retreated from the brink of the abyss of nuclear war.
Subsequent events caused the fears of nuclear attack on both sides to diminish significantly, as the tensions between the superpowers decreased, and have remained—at least in nuclear terms—comparatively low. However, the present indicates that this might be changing. Relations between the two have recently fallen to new post-Cold War lows, and events have illustrated that the world may be heading back towards a more tense situation in terms of nuclear armament and use, possibly even to a first strike. Talk that has been characterized as "reckless" has been rife amongst certain U.S. politicians who favor the development of new nuclear weapons (such as through the Complex 2030 program) or new uses for old weapons, such as by using them as nuclear bunker busters, even against non-nuclear states. The military invasion of Iraq was seen by Russia as indicating potential U.S. disrespect for what the Russian leadership views as international law, which it allegedly values. The U.S. missile defense program has proven a persistent irritant to better relations with Russia, who views the placement of U.S. missile defense systems in Eastern Europe for defense against "the Iranian threat" similar to how the U.S. would view placement of Russian missile defense systems in, say, Cuba, for Russian defense against "the insidious Kiwi". The assasination of a British citizen by alleged operatives of the Russian government using Polonium-210, a radioactive poison, as well as the poisoning by dioxin of the President of the Ukraine, has raised tensions between Russia and the West, with Western nations regarding the poisonings as an indicator of the character, morality, and true intentions of the Kremlin. On top of that, Russian bellicosity and belligerence has recently increased, with tests of new nuclear-capable missiles occurring on a regular basis, military conflicts with neighboring states, claims of a Russian "sphere of influence" on the perimiter of the old Soviet Union, the rise of neo-fascist "Putin Youth" groups, aggressive politicization of and threats of withdrawal of natural gas supplies to Europe, should the Europeans not dance to the Kremlin beat, and even threats of a nuclear first strike against Poland have been heard to be made by certain Russian generals.
Other nations have engaged in other policies that are regarded as potentially destabilizing. Officials in the People's Republic of China recently tested an antisatellite missile, leading to widespread international concern, as antisatellite missiles are viewed as threats to nuclear-launch warning systems, which could easily result in a first strike; in addition, tensions amid the Chinese governments over Taiwan have been rife in recent years; in addition, the PRC is reportedly pursuing modernization of their nuclear forces. Israel has made threats of the use of weapons, including those of a non-conventional character, while the U.S. has refused to "take options off the table" (including the "nuclear option"), in the nuclear dispute with Iran, who is widely viewed as pursuing a clandestine nuclear weapons program, and well known for their desire for the destruction of Israel (c.f. "The World Without Israel") and extreme dislike for the United States (c.f. regular political rallies in Tehran calling for "Death to America!"). The unpredictable North Korean government recently tested (or, more likely, partially fizzled) a nuclear device, and has historically threatened to turn Seoul into a "sea of fire", or most recently, "ashes", in response to unspecified, but always imminent, U.S. or South Korean "aggression" against the Worker's Paradise. The foreign relations of Pakistan and India, as always, remain a powder-keg, but are now exaggerated by the nuclear arsenals of both states, as well as the rise of Hindu fascism in India, and the rise of al-Qaeda Islamism in Pakistan, and intercommunal strife--ranging from the demolition of a historic mosque by communal hooligans with worshippers inside--to a terrorist assault on Hindu shrines could be the spark igniting a nuclear war.
Both sides never sought nuclear conflict, even though it threatened to break out on multiple occasions. What both sides had, however, was a deep and continuing fear—one might even call it a paranoia—that the other nation was seeking to start a nuclear conflict, or, at least, thought such a conflict was "winnable" and would not be deterred by the threat of nuclear war. This led to both sides adopting aggressive, confrontational military and nuclear strategies that were misinterpreted and countered by the other side, furthering distrust. These strategies led to destabilization of the strategic situation to the point where the two major war scares of the Cold War occurred: the Cuban Missile Crisis and the Able Archer/VRYAN crisis. Though neither side intended to start a nuclear war, and, in fact, were mortally terrified of the possibility of it, neither side adopted strategies to calm things down, so sure were they of their adversaries' bad faith.
U.S. military strategy (at least in Europe) was confined to responses to potential Soviet aggression against NATO countries. Soviet military theory was dominated by the theory of the "deep operation" - a large scale combined-arms offensive into enemy-held territory - rather than a nuclear offensive. Soviet conventional superiority, shown by the fact that the Soviet Union certainly was prepared for war in Europe, having massed armored, mechanized, artillery, and air forces poised along the Inner German and Czech borders, led by the dread Third Shock Army of the Soviet Union, caused NATO to consider the use of tactical nuclear weapons to stop the "steamroller" of the Red Army if they decided to take a drive through the Fulda Gap or an amble through the North German Plain. NATO's position changed in the 1970s and 80s, in favor of trying to stop a Soviet offensive through the employment, at least initially, of a doctrine involving non-nuclear AirLand Battle to try to buy time to either throw back the invader or work out the issues at hand through diplomacy. Both sides, however, were willing to use nuclear weapons, if necessary, to not lose the war at hand. Although neither side was actively pursuing a first-strike policy—since the time of Khrushchev, the leaders of orthodox communism believed that "peaceful coexistence" with the "imperialist" powers was possible—both sides relied on military strategies that could have still caused a general nuclear war.
Ideological determinism also played a role. President Ronald Reagan of the United States, at least before the Able Archer/VRYAN crisis, believed that everybody, including the Soviet Union, was completely aware of the United States' good intentions, even when he bellicosely declared that the USSR was an "evil empire" and (more jokingly) that the "bombing begins in 5 minutes" while encouraging the military to conduct threatening exercises, such as sneaking a Carrier Battle Group through the GIUK Gap and sending nuclear-capable bombers towards the territory of the USSR. Chairman Andropov of the Soviet Union had similar, distorted views; he believed that the Western Allies, and the U.S., in particular, were fascist states, whose leaders had territorial designs against the Soviet Motherland on the scale of Napoleon, at the least, and Hitler, at the worst; in addition, to counter the "fascists", he incited his military-industrial complex to build weapons such as the SS-20 MIRV IRBM and the SS-18 Satan MIRV ICBM, which the NATO countries reasonably viewed as a Soviet sword against their throats, and caused reaction through development of equivalent or superior weapons systems.
Luckily for the world, when the superpowers drew close to the edge of the nuclear abyss during both the Cuban Missile Crisis and the Able Archer/VRYAN Crisis, they took the time to stare intently into its depths, and came away knowing that the abyss stared back into them. They learned and grew from their mistakes and miscalculations that led them to be within view of mutual assured destruction. Andropov was followed by Gorbachev, and Gorbachev brought a far less hostile, ideological, and reflexively skeptical approach to the relations between the superpowers, helping to build an atmosphere of trust between the two. Reagan had a figurative conversion on the road to Damascus regarding nuclear weapons and (especially) ICBMs following this crisis, discarding his preconcieved notions of general Soviet bad faith, leading him to come full circle and famously declare that "Nuclear war cannot be won and must not be fought". These new attitudes on both sides nearly brought about the disarmament and destruction of ICBMs, long-range SLBMs, and, possibly even nuclear weapons themselves at a groundbreaking disarmament summit between Gorbachev and Reagan at Reykjavik in 1986. (The sticking point causing agreement to be unreachable was the SDI Program, just as missile defense continues to be a thorn in the side of the Russians today.) However, progress was made; the INF Treaty, the Conventional Forces in Europe Treaty, and the START Treaty could be said to be the result of the change in leaders and leaders' attitudes that the Able Archer/VRYAN crisis facilitated, just as the Non-Proliferation Treaty and the Partial Test Ban Treaty, as well as U.S.-Soviet détente, could be considered to be the sons and daughters of the Cuban Missile Crisis. Still, both crises were dangerous times catalyzed by dangerous political and military mistakes caused by dangerous policies instituted by leaders who let their fear get the better of their judgment and reasoning. Thankfully for those who lived, and those who now live, these mistakes never caused a first strike to come to pass.
For both the U.S. and Russia, as well as the other nuclear powers, full countervalue retaliation would be the likely fate for anyone who unleashed a first strike. So as to ensure that this is the case, the nuclear-weapons states have taken measures to ensure that their retaliatory strikes will get through.
Nuclear-powered submarines carrying submarine-launched ballistic missiles, called SSBNs (Russian: РПКСН), and commonly known as "boomers", are widely considered the most survivable component of the nuclear triad. The depths of the ocean are extremely large, and nuclear submarines are highly mobile, very quiet, have virtually unlimited range, and can generate their own oxygen and potable water; in essence, their undersea endurance is limited only by food supply. It is unlikely that any conceivable opponent of any nuclear power deploying SSBNs could locate and neutralize every ballistic missile submarine before it could launch a retaliatory strike, in the event of war. Therefore, to increase the percentage of nuclear forces surviving a first strike, a nation can simply increase SSBN deployment, as well as deployment of reliable communications links with SSBNs.
In addition, land-based ICBM (МБР) silos (ШПУ) can be hardened. No silo can really defend against a direct nuclear hit, but a sufficiently hardened silo could defend against a near miss. In addition, ICBMs can be placed on road or rail-mobile launchers, which can then be moved around; as an enemy has nothing fixed to aim at, this increases their survivability.
By adopting a launch on warning nuclear posture, the possibility of a first-strike can be significantly mitigated. Of course, the possibility of an accidental nuclear war is vastly increased, as early-warning system malfunctions (which have occurred several times), especially in periods of politico-military tension, could easily lead to nuclear war.
Looking Glass, Nightwatch, and TACAMO are U.S. airborne nuclear command posts, and represent survivable communication links with U.S. nuclear forces. In the event of significant political-military tensions between the nuclear powers, they would take to the skies, and provide survivable communications in the event of enemy attack. They are capable of the full exercise of all available MAOs (Major Attack Options), as well as the full SIOP, in the event of a first strike, or the destruction of the NCA. They can directly initiate launch of all U.S. ICBMs via radio and satellite communication, signal SLBMs to launch, and send bombers on their strike missions. In addition to these airborne assets, the U.S. government has several command and control bunkers, the most famous of which is NORAD, tunneled a few thousand feet into the granite of Cheyenne Mountain, outside of Colorado Springs, Colorado, which is believed to be capable of surviving a direct nuclear hit. Other U.S. C4ISTAR bunkers include an installation called Site R, located at Raven Rock, Maryland, which is believed to be the Pentagon's relocation site if Washington, D.C. is destroyed, as well as Mount Weather, in Virginia, which is believed to be the relocation site for top Executive Branch officials. The Greenbriar in West Virginia was once the site of the Supreme Court of the United States and Congress' relocation bunker; however, it is no longer a secret and is now a tourist attraction.
The Russians also have equivalent or superior capabilities in this area; they have a system called СПРН, which is capable of detecting nuclear launches and providing early warning, so that any such strike would not be undetected until it is too late. But their unique and special capability can be found with their Dead Hand fail-deadly computerized nuclear release system, based at Mount Yamantaw in the Urals. Apparently, Dead Hand, named for either the Dead Man's Hand in poker, or the Dead Man's Switch in dangerous or deadly machinery, can be turned on in the event that the Russian leadership fears a nuclear attack. Allegedly, once Dead Hand is activated, if it detects a loss of communications with Moscow as well as nuclear detonations inside of Russian territory, it can give final authority for the release of nuclear weapons to military officers in a bunker under Mt. Yamantaw, who can then, if they so determine, launch Russia's arsenal. Mt. Yamantaw is believed to be able to withstand multiple direct nuclear detonations.
Instead of relying on sophisticated communications links and launch-on-warning postures, the French, British, and Chinese have chosen to assume different nuclear postures more suited to minimum credible deterrence, or the capability to inflict of unacceptable losses so as to prevent the use of nuclear weapons against them, rather than pursuing types of nuclear weapons suitable to first-strike use.
The People's Republic of China is believed to pursue a minimum credible deterrent/second strike strategy with regards to the United States. This may or may not be true with regards to the PRC's stance vis a vis Russia, as the majority of Chinese nuclear platforms are non-intercontinental, and are deployed on the Russian-Chinese border. Unlike the relations of the United States and the PRC, the PRC and Russia have had military conflicts in the past. In recent years, the PRC has improved its early-warning systems and renovated certain of its platforms for intercontinental strike; this may be due to the U.S. missile defense system (it may not be, however). In general, it appears that the PRC's leaders do not greatly fear a first strike (due to their posture of merely inflicting unacceptable losses upon an adversary as opposed to the U.S./Russian policy of trying to "win" a nuclear war); in any event, the Chinese arsenal is considered sufficient to ensure that such a first strike would not go unavenged.
France & Great Britain possess sophisticated nuclear weapons platforms; however their nuclear strategies are believed to be minimum credible deterrent-based as well, due to the small number of weapons they possess and lack of major adversaries they have.
MIRVed land-based ICBMs are generally considered suitable for a first strike or a counterforce strike, due to:
Unlike a decapitation strike or a countervalue strike, a counterforce strike might result in a potentially more constrained retaliation. Though the Minuteman III of the mid-1960s was MIRVed with 3 warheads, heavily MIRVed vehicles threatened to upset the balance; these included the SS-18 Satan which was deployed in 1976, and was considered to threaten Minuteman III silos, which led some neocons to conclude a Soviet first strike was being prepared for. This led to the development of the aforementioned Pershing II, the Trident I and Trident II, as well as the MX missile, and the B-1 Lancer.
MIRVed land-based ICBMs are considered destabilizing because they tend to put a premium on striking first. When a missile is MIRVed, it is able to carry many warheads (3 to 14 in existing U.S. missiles; 3 to 12 in existing Soviet missiles) and deliver them to separate targets. If it is assumed that each side has 100 missiles, with 5 warheads each, and further that each side has a 95 percent chance of neutralizing the opponent's missiles in their silos by firing 2 warheads at each silo, then the attacking side can reduce the enemy ICBM force from 100 missiles to about 5 by firing 40 missiles with 200 warheads, and keeping the rest of 60 missiles in reserve. As such, this type of weapon was intended to be banned under the START II agreement, however the START II agreement was never activated, and neither Russia nor the USA has adhered to the agreement.