From the Daily Beast here:
The Budget Control Act capped all federal discretionary spending—basically, all budget lines except health and retirement entitlements—through the 2021 fiscal year. The way the caps are calculated is complex. To put it simply, the government required itself to eliminate $2.4 trillion in planned spending over 10 years starting in 2011.
The caps have translated into lower budgets than the Defense Department deems necessary to pay troops, operate equipment and develop and buy new technology. Yes, the Pentagon still spends about $600 billion annually, not counting funding for frontline operations. But that number should be tens of billions higher, Mattis and other senior military officials have argued.
Oh, fuck off.