In addition to anti-Manchurism and anti-imperialism, political scientist Chalmers Johnson has argued that the rise of power of the CCP through its alliance with the peasantry should also be understood as "a species of nationalism." Johnson observes that social mobilization, a force that unites people to form a political community together, is the "primary tool" for conceptualizing nationalism. In the context of social mobilization, Chinese nationalism only fully emerged during the Second Sino-Japanese War (1937-1945), when the CCP mobilized the peasantry to fight against the Japanese invaders. Johnson contends that early nationalism of the Kuomintang was quite similar to the late nineteenth-century nationalism in Europe, as both referred to the search for their national identities and positions in the modern world by the intelligentsia. He argues that nationalism constructed by the intellectuals is not identical to nationalism based on mass mobilization, as the nationalist movements led by the Kuomintang, as well as the May Fourth Movement in 1919, were not mass movements because their participants were only a small proportion of the society where the peasants were simply absent. When the Second Sino-Japanese War broke out in 1937, the CCP began to mobilize the Chinese peasantry through mass propaganda of national salvation () Johnson observed that the primary shift of the CCP's post-1937 propaganda was its focus on the discourse of national salvation and the temporary retreat of its Communist agenda on class struggle and land redistribution. The wartime alliance of the Chinese peasantry and the CCP manifests how the nationalist ideology of the CCP, or the peasant nationalism, reinforced the desire of the Chinese to save and build a strong nation.