WASHINGTON — Defense cuts likely to ensue from the failure of the Obama administration and Congress to agree on the budget would jeopardize U.S. security, according to a Jewish Institute of National Security Affairs paper.

“The cuts now being contemplated vastly exceed anything the United States has experienced in the post-World War II era,” said the introduction to a JINSA paper published this week that compiles analyses from former officers of all five branches of the U.S. military.

“While projections of future defense increases after many years of decline make the scenarios being used look less severe,” the paper said, “there is nothing to assure the American people and our allies that, given the serious fiscal condition in which we now find ourselves, defense spending will not only continue to decline as required by the 2011 budget agreement, but may be cut further as our political leadership avoids reforming our entitlement culture and bringing the U.S. fiscal house, tax code and investment strategies into the 21st century.”

A number of top defense officials in recent weeks have decried the possible $1 trillion in defense cuts ensuing from the failure of last year’s congressional “supercommittee” to agree on a budget that would address the national debt. The agreement to set up the supercommittee included automatic across-the-board cuts should it fail to come up with a proposal that Congress would pass.

U.S. Defense Secretary Leon Panetta has said that the effect could be “devastating.”

The cuts, JINSA said, “would jeopardize our security, demoralize our allies, and embolden our adversaries.”

JINSA experts expressed particular concern about cuts to modernization and to benefits to troops, which they said could drive some of the military’s most capable personnel into civilian life.