For only the fifth time during his entire presidency, Barack Obama exercised his veto, knocking down a defense authorization bill that would essentially expand retirement benefits for veterans, among many, many others things — including, not only controversial green lights for additional/continued spending, but enact a restructure of how the military budgets itself in the first place.

It would also prohibit the transfer of prisoners being held at Guantanamo Bay.

This from the Washington Post:

The White House said that the National Defense Authorization Act (NDAA) would tap an overseas contingency operations account designed for emergencies and war costs and use it as a “slush fund” to avoid budget restrictions. Those restrictions — known as sequestration — would impose offsetting across-the-board cuts if spending passed certain levels.

“The president believes that the men and women who serve in our armed forces deserve adequate and responsible funding, not through a gimmick or not through a slush fund but one that would — could withstand scrutiny,” said White House spokesman Eric Schultz.

The veto is a shot across the bow of Congress, which differs with Obama over the outlines of a budget for fiscal 2016. And Obama made an extra point by publicly signing the veto statement before a pool of White House press. The fiscal year ended Oct. 1 and a continuing resolution will temporarily keep the government open through Dec. 11.

According to Washington insiders, Obama is confident the House will uphold his veto.

For more of the details of the changes in military veteran benefits included in the bill, click here.