The 2A _has_ been badly weakened. Ever since the NFA of 1934, the right to keep and bear arms has been increasingly infringed upon in an almost monotonic manner.
Machine gun? Hand grenade? Howitzer? Missile launcher? Flamethrower? Can you make a cogent argument that claims these are not arms?
The US Armed forces cannot use nuclear bombs upon the citizens of the USA without employing them upon the USA. Accordingly, your argument is nonsensical.
I get that there is a disparity. How'd that work out in Viet Nam? Did they capitulate?
And this disparity is actually a result of the ever increasing infringement upon the 2A.