Ask any defense lobbyist in Washington—spending on defense is threatened like no time in recent memory. Under the Budget Control Act, the budget for defense will be subject to a strict cap (a process known as sequestration) beginning in 2014 and lasting until 2021. This would necessarily create steep, across-the-board reductions in defense spending.

But nobody on either side of the aisle is enamored with this defense cap. The House GOP budget plan, written by Paul Ryan, does away with the sequester, and not only protects defense spending from cuts, but boosts the level of spending. House Speaker John Boehner plans a bill this year to officially junk the sequester.

As we’ve been flagging here for weeks, President Obama’s budget also does away with the defense sequestration. This has concerned some liberals—since an overall cap on discretionary spending will presumably remain in place, many worry that removing the limit on defense will lead Congress to take a vast majority of the reductions from social programs and leave defense untouched.

This morning I spoke with Representative Barney Frank, a leading voice in Congress for cutting defense spending. (He has frequently advocated a 25 percent reduction in the Pentagon budget, a goal he repeated at a public event before we spoke). Frank blasted the Ryan/Boehner plans for defense spending as “outrageous”—but he was not concerned with Obama’s removal of the defense sequester per se.

Frank’s issue with the defense sequester is that it mandates across-the-board cuts—meaning that military pensions and salaries would come under the knife right along with everything else.

“I would like to keep the sequester in place but have more flexibility as to how it’s done,” Frank said. But even if the sequester goes, and there’s a single discretionary spending cap until 2021, Frank said he wasn’t overly concerned.

“Things have changed,” he said. “[Cuts slanted heavily to domestic programs] would clearly have been the case ten years ago. But I think Medicare versus military, we have a much better chance now. I prefer not to do that, but I believe the single cap—we would still get substantial military cuts.”

In any case, Frank sees the battle playing out in the public sphere, not according to relatively arcane provisions of the Budget Control Act. “Mechanics don’t do this, it’s political will,” he said. “If we have the votes to make substantial defense reductions, we’ll have it. If you don’t, the sequester is not made out of steel. It’s like the Great Wall of China, it looks tougher than it is.”

While Frank is generally behind Obama’s plan to ease the defense sequester while continuing to cut defense, he thinks the president doesn’t cut far enough, and he needs to be pushed. “He’s better than Republicans, he’s not good enough. He needs to be pressed to do more in reductions,” Frank said. “The president is for too much military spending but he’s not where Boehner is. The president specifically said he’s not going to exempt defense from further cuts and make them up elsewhere.”

In all, as Frank noted several times, this is a battle that can only really be played out after the presidential elections. The sequester will loom, and if Republicans take Congress and the White House, you can virtually guarantee a version of the Ryan budget comes to fruition—no cuts in defense spending, perhaps even an increase, with the difference made up in domestic programs. If Democrats prevail, or if the result is mixed, then the bargaining begins. But don’t count on the defense sequester as-is to survive.