Defeatism is acceptance of defeat without struggle. In everyday use, defeatism has negative connotation and is often linked to treason and pessimism, or even a hopeless situation such as a Catch-22. The term is commonly used in the context of war: a soldier can be a defeatist if he or she refuses to fight because he or she thinks that the fight will be lost for sure or that it is not worth fighting for some other reason. Again in connection with war, the term is used to refer to the view that defeat would be better than victory. The term can also be used in other fields, like politics, sport, psychology and philosophy.
Initially rejected by all but the more radical at the socialist Zimmerwald Conference in 1915, the concept appears to have gained support from more and more socialists, especially in Russia in 1917 after it was forcefully reaffirmed in Lenin's April Theses and Russia's war losses continued.
Revolutionary defeatism can be contrasted, using Lenin's terminology, to "revolutionary defencism" and to social patriotism.