I assume it doesn't actually work like that in practice.
What exactly would you have to do with the $990 billion dollars to wipe out poverty for 10 years? Give it to the poor?
ok let's assume you do.
There's now x number of soldiers out of work
Munitions workers
Aircraft and tank manufacturers
000;s more people who work in and around the military bases and rely on them for their livelihoods
The list goes on.
You won't 'solve' the problem just move it about a bit.
It's the same argument as the people who said billions of dollars were wasted going to the moon. We didn't actually just go in to space and burn a few million notes. All the money was spent keeping people in jobs.