Military Resistance is a factor given as a % and used by Nod EVA and used in relation to nations. It represents not the actual military strength of the nation but how much of the national military forces would actually resist were Nod forces to attempt to install a friendly regime in power at the expense of the existing regime. National military forces in this case probably represent the entirety of the militery forces of a given nation that are active, including armed rebels. It probably does not represent foreign forces present in the nation including core GDI forces.