There are all kinds of negative potentialities here but there are also positive ones in that small professional units operating under great power supervision may in some instances be better than:

a) Doing nothing

b) Relying on the most poorly disciplined, led and trained armies of the world to be at the forefront of UN peacekeeping.

c) Letting virtually unarmed UN peacekeepers become accesssories to atrocities via ineffectuality, as in Bosnia.

While Tom's caveats are well-taken the current system is nothing to write home about either.