actually, ts asking this question is like asking which car is
the fastest. Different cars can be the fastest depending on the
variables that they are tested against. For example in under 1.6
cat could be xxx car, but say from 2-3litre cat could be this yyy
car. And somemore, fast also have different type of fast. Fast in
acceleration to 100mph, fast in a straight road, fast in wet
condition, fast in 50 lap F1 race... etc. The variables are
endless.
hence it is difficult if not impossible to determine which is
the most powerful country. It's not just about the military
hardware, but also the quality of the hardware, the ability of the
people to use it, the sustainability to using it, the mental
backlash on the soldiers as well as the civilians at home (Let's
not forget his troops fought life and limb overseas, Thomas
Jefferson fought an equally difficult if not harder war of
convincing his country men to continue to support the war). There
are also other avenues of "power" to consider for example
controlling the economy, hacking the intelligence network and
selling sensitive info to potential rivals, etc.
But having said all this, i believe in hand to hand, solider to
solider, the most dangerous solider would be one from NK. There is
a limit how much an american soldier fights and risks his life as
he has family, assets and country behind him. A NK fighter will go
all out because they have nothing in the first place. If they fail,
they have nothing. If they win, they have everything.