Virulent anti-nationalists are generally marxist leninist communists.
The rhetoric of the anti-nationalists is generally implicitly or explicitly "internationalist". In early Communist organization names they often used the word "international" and I think they even have a toe tappin' song by that name:
And if you doubt the second part "are often pro-war" this is the doctrine of divide and conquer, civil war (called "class war") in which the target of their anti-nationalist colonialism is provoked into disorder before the "forces of liberation" can swoop in and expand the mother country.
