i wouldn't worry too much. we won't have any big war until trade between major powers is going on. if there will be a major (nuclear war) then we're all f*****.
i believe modern warfare is in small, mobile and stealthy units. the cold war is history. the US military is slowly realizing this by scraping the F22 program and investing into UAVs.
as for NK or Iran getting such weapons...they probably will, but i doubt they'd use them, since it would cause massive repercussions. they're more of an deterrent than anything else.