See studies by Q. Wright (2d ed. 1965), G. Blainey (1973), J. Keegan (1976), and V. D. Hanson (1989, 1999).
In the Middle Ages the ideals of knighthood restrained some cruelties in warfare, but systematic legal codes did not appear until the 17th cent. The great work of Grotius, De jure belli ac pacis [on the laws of war and peace] (1625) and the works of Vattel had much influence in introducing humane practices. Detailed international treaties governing war are mostly a product of the 19th and 20th cent. The Declaration of Paris (1856; see Paris, Declaration of), the accords concluded at the Hague Conferences (1899, 1907), and the Geneva Conventions (1864, 1906, 1929, 1949) are the main bodies of formulated law.
There is no convention on the laws of war to which all the major powers of the world have acceded, and many conventions provide that their terms shall be inoperative if any of the belligerents is not a signatory or if an enemy commits a violation. Despite such provisions, many nations have adopted the laws of war, and the conditions of warfare have undoubtedly been ameliorated, particularly in the treatment of prisoners and the consideration shown to the sick and wounded. The care of the sick and the wounded is facilitated by making medical personnel noncombatants and by clearly marking hospitals and similar installations, thus sparing them from attack. Conventions restricting the use of certain weapons probably have not materially mitigated the horrors of war. For the most part, only those weapons that are of limited military use, e.g., poison gas, have been effectively banned, while efforts to prohibit militarily effective weapons, e.g., atomic weapons and submarine mines, have not succeeded.
The laws of war have had as their objective the protection of civilian populations by limiting all action to the military. A distinction was made between combatants and noncombatants, the former being defined in terms of traditional military units. Thus combatants must have a commander responsible for subordinates, wear a fixed and recognizable emblem, carry arms openly, and follow the laws of war. But the development of aerial bombing in World War I and of guerrilla forces dependent on civilians has tended to make all enemy territory part of the theater of operations. New practices and categories have yet to be worked out to protect civilian centers adequately.
Civilians in territory occupied by the enemy are, however, supposed to be entitled to certain protections. There may not be imprisonment without cause, and fines may not be levied upon a whole civilian population for individual offenses. Private property also receives limited protection, and it may not be confiscated for military use unless fair compensation is paid. Special rules govern such actions against property as the taking of a prize at sea or in port, the confiscation of contraband, and the use of the blockade. Property destroyed in the course of action against the enemy is, of course, not compensable. Places of religious, artistic, or historical importance should not be attacked unless there is military need.
No direct diplomatic relations exist between belligerents, but neutral diplomats are often given custody of property in enemy territory and are entrusted with negotiations. In the field of combat, passports, safe-conducts, and flags of truce permit consultations between opposing commanders. Hostilities may even be totally suspended by an armistice, which is often the prelude to surrender.
Violations of the laws of war have probably occurred in all major conflicts; a nation confident of victory will frequently not be deterred even by fear of reprisals. After World War II the military and civilian leaders of the Axis Powers who were responsible for violations were tried for war crimes, and some Americans were tried for war crimes in the Vietnam War (see My Lai incident).
See M. Greenspan, The Modern Law of Land Warfare (1959) and The Soldier's Guide to the Laws of War (1969); S. D. Bailey, Prohibitions and Restraints in War (1972).
The French began to seize American ships trading with their British enemies and refused to receive a new United States minister when he arrived in Paris in December 1796. In his annual message to Congress at the close of 1797, President John Adams reported on France’s refusal to negotiate and spoke of the need "to place our country in a suitable posture of defense." In April 1798, President Adams informed Congress of the "XYZ Affair", in which French agents demanded a large bribe for the restoration of relations with the United States.
The French inflicted substantial losses on American shipping. Secretary of State Timothy Pickering reported to Congress on June 21, 1797 that the French had captured 316 American merchant ships in the previous eleven months. The hostilities caused insurance rates on American shipping to increase at least 500 percent, as French marauders cruised the length of the U.S. Atlantic seaboard virtually unopposed. The administration had no warships to combat them; the last had been sold off in 1785. The United States possessed only a flotilla of revenue cutters and some neglected coastal forts.
Increased depredations by privateers from Revolutionary France required the United States Navy to protect the expanding merchant shipping of the United States. The United States Congress authorized the President to acquire, arm, and man no more than twelve vessels, of up to twenty-two guns each. Under the terms of this act, several vessels were purchased and converted into ships of war.
July 7, 1798, when Congress rescinded treaties with France, can be considered a semi-official beginning of the Quasi-War. The act was followed two days later with Congressional authorization to attack French vessels.
Of all of the vessels operating under command of the U.S. Navy, only one vessel was captured by—and later recaptured from—French forces: USS Retaliation. Retaliation was the captured privateer La Croyable, recently purchased by the U.S. Navy. Retaliation departed Norfolk on October 28, 1798, with Montezuma and Norfolk and cruised in the West Indies protecting American commerce. On November 20, the French frigates L’Insurgente and Volontaire overtook Retaliation while her consorts were away on a chase and forced commanding officer Lieutenant William Bainbridge to surrender the out-gunned schooner. However, Montezuma and Norfolk escaped after Bainbridge convinced the senior French commander that those American warships were too powerful for his frigates and induced him to abandon the chase. Renamed Magicienne by the French, the schooner again came into American hands on June 28, when a broadside from USS Merrimack forced her to haul down her colors.
Revenue cutters in the service of the Revenue-Marine, predecessor of the Coast Guard, also assisted in capturing two others. The cutter USRC Pickering, commanded by Edward Preble, made two cruises to the West Indies and captured ten prizes, one of which carried 19 guns throwing 150 pounds of iron compared to Pickering’s 14 guns and total iron weight of only 56 pounds, and was manned by some 250 sailors, more than three times Pickering’s strength.
Sources differ with regards to American losses. One contends that by the war's end in 1800, the French had seized over two thousand American merchant vessels. Another claims that the United States lost only one. (This and similar discrepancies may be explained if one is counting naval losses and another merchant ships.)
Although they were fighting the same enemy, the Royal Navy and the United States Navy did not cooperate operationally, nor did they share operational plans or come to mutual understandings about deployment of their forces. The British did sell the American government naval stores and munitions. In addition, the two navies shared a system of signals by which each could recognize the other’s warships at sea and allowed merchantmen of their respective nations to join their convoys.