The firearms are not enough. The Mukti Bahini were heavily assisted by members of India's Research and Analysis Wing. India provided weapons, ammunition, logist

The firearms are not enough. The Mukti Bahini were heavily assisted by members of India's Research and Analysis Wing. India provided weapons, ammunition, logistical support, and many of the refugees who volunteered were recruited and trained on Indian soil. Months before the revolution had even started Indian spies fabricated evidence linking Pakistan to the 1971 Indian Airlines hijacking, which India used to justify a ban of all Pakistani flights across its airspace, preventing Pakistani carriers from resupplying East Pakistan by air. Indira Ghandi herself was basically a foreign ambassador for Bangladesh, traveling the world not only to drum up political support for the cause, but to also to justify India's impending war with Pakistan to the international community. India and the USSR went to bat for Bangladesh at the UNSC, and India was the first U.N. state to give Bangladesh diplomatic recognition. Bangladesh also had many allies among warsaw pact countries such as the GDR (East Germany), Bulgaria, Czechoslovakia, Hungary, Romania and the Soviet Union, during the war. All of whom supported the cause in some way, be that medical services for wounded soldiers, diplomatic/economic support, scholarships for Bangladeshi students or other things. That's what separates Bangladeshi force from 99% of NRA wingnuts: training, organization, support from foreign allies. Because of these differences, I do not expect a similar international response to occur in the event of a civil war in the U.S. And I think such is ultimately what will make or break an insurgency.