UPDATED to clarify WASHINGTON: Senate authorizers will probably go along with the House in adding $18 billion to the base defense budget, setting up a veto fight with the White House. After all, it was Senate Armed Services chairman John McCain himself who sponsored the $18 billion plus-up in the Senate, where it was narrowly defeated. Today, SASC’s staff director, Chris Brose, gave what we’d consider strong clues that McCain would agree to add the money in the upcoming House-Senate conference on the National Defense Authorization Act.

That said, the House and Senate approaches on how to add the money are significantly different, so majority support for McCain’s model doesn’t guarantee a House-Senate compromise will pass the Senate.

On the surface, Brose and his House Armed Services counterpart, Bob Simmons, were carefully noncommittal in this afternoon’s extraordinary on-the-record event at the conservative American Enterprise Institute. (The normally reclusive staff directors spoke to the public for an hour and another 30 minutes to media only). But the message between the lines seems clear to us.

“The chairmen haven’t even got together (and) this is something that they need to sit down and talk through,” Brose said when one reporter asked him directly about the $18 billion. But in his very next sentence, he said this: “All I can say on it today is you saw the amendment Sen. McCain offered on the floor. It didn’t get 60 (votes), but it got a majority.”

That point is critical: While an ordinary amendment like McCain’s faces filibuster and thus effectively requires 60 votes to pass, a conference report is a “privileged motion” and only requires a simple majority.

“The majority of both the House and the Senate, bipartisan, voted that the funding was not adequate,” emphasized Bob Simmons, the House Armed Services staff director.

Certainly, the two staff directors were in synch on the need for more money. Asked about potential gimmicks to pay for modernizing the nuclear deterrent, “the answer here is, let’s actually fund the requirements that our nation has,” Brose replied.

“Yeah, if you get the topline up where it needs to be, you solve the problem,” Simmons added enthusiastically.

“We need an Ohio Replacement (submarine), we need a new bomber, we need nuclear modernization, and we need to pay for it, and we need to pay for it not at the expense of conventional modernization. So ultimately this is a debate about funding,” continued Brose. “Let’s actually fund the requirements that our military has.”

That sounds like an argument for the $18 billion.

South Dakota National Guard soldiers on duty in Afghanistan.

What about the administration’s criticism — including some sharp comments from Defense Secretary Ash Carter — that the $18 billion is a fiscal gimmick that undermines the war effort, transferring funds from operations in Afghanistan and Iraq to other, less urgent needs?

“To say that we took it from the warfighter is incorrect… wholly incorrect,” said Simmons. “The funding we put in was to fund the next to deploy,” he said, who are chronically short-changed and therefore unready. That’s a real and glaring need, he said.

That said, the House admits their approach will mean funding for ongoing combat operations will run out partway through the year, requiring a supplemental emergency spending bill. Simmons & co. point out that the Democratic-controlled Congress passed just such a partial-year of war funding in 2008-2009, to give room for the incoming administration to request a supplemental tailored to its own spending priorities. That’s “absolutely rational,” Simmons said.

The difference between now and 2008, of course, is that we now have a Budget Control Act (aka sequestration), as amended by last year’s hard-won budget deal, the Balanced Budget Act (BBA). “The budget stability that was supposed to last for two years is already under threat after only six months,” Carter argued in May.

“I don’t see how it blows up the BBA. The BBA sets the total defense spending at $610; so we dictated how we’re going to spend the $610 billion,” Simmons said. It’s just a different allocation than the administration proposed, he said. “The only way it blows up the BBA is if the president vetoes it and says, ‘you must spend the money, Congress, exactly the way I tell you.’”

Yes, the House approach requires a supplemental spending bill to be passed next year, but the BCA doesn’t block that, because it doesn’t cover supplementals, only the base budget. The BBA (last year’s budget deal) doesn’t get in the way either, because it will have expired, he argued.

“There’s a cliff anyway,” Simmons said. Regardless of whether the House measure is enacted or not, “we’re going to have a debate over the budget next year because there’s no deal.”