"America is going broke, and yet we still spend about as much on "defense" as all other countries combined."
FALSE. The US doesn't spend that much on defense as all other countries combined. Not even close. According to the SIPRI, whose figures are also available on Wikipedia, the US spends only 41% of the world's total military spending, and that's if you accept SIPRI's grossly OVERSTATED figures for the US and UNDERSTATED figures for China and Russia. If you accept that China and Russia spend far more than SIPRI admits to, America's share of global military spending is even lower.
The US can safely afford its current military budget. It amounts to just 4.2% of America's GDP and less than 17% of the total federal budget.