[updated Wednesday with remarks from Sen. Ayotte, Sen. Kyl, and James Carafano] Tomorrow morning, one of the Republican Party’s rising stars, Sen. Kelly Ayotte, will kick off a new project co-sponsored by two of its long-established institutions, the Heritage Foundation and the American Enterprise Institute. The official agenda of the “Project for the Common Defense” is to build a new bipartisan consensus on national security. But the first challenge, the organizers acknowledge, is to rebuild some kind of national security consensus among Republicans.

“It would be wonderful if we could spark a revival of interest in national security issues among liberals and Democrats,” said Tom Donnelly, who’s helming the project at AEI. (James Carafano is his counterpart at Heritage). “But we’re also realistic about the political landscape as it is… As much as we don’t want to form a circular firing squad among conservatives – and as much as that story line is catnip to the mainstream media – we do want to have a conversation about the need for American military strength.”

As the ongoing stalemate over sequestration shows, in addition to all the bitter divisions between the two parties, GOP defense hawks and budget hawks have split over defense spending. At issue is whether the military is too important to be subjected to the same steep cuts as other discretionary spending, as is happening under the Budget Control Act as currently written.

“Here we have this sequester which everybody has condemned, so how does a system [still] do something that everybody condemns and everybody believe is against the national interest?” asked former Senator Jim Talent, a senior fellow at Heritage and one of the project’s architects, in a Monday evening phone call. “[It’s] a lack of clarity about why defense is important, so it just becomes another mouth that has to be fed.”

Not so long ago, defense spending was sacrosanct in most Republican eyes. [Updated: As Sen. Ayotte argued on Wednesday, “as the party of Ronald Reagan, we shouldn’t have put our military on the chopping block.” Added Ayotte, her voice rising in a rare moment of passion in her otherwise measured speech, “I didn’t vote for sequestration, [but] the party of Ronald Reagan joined up with this administration to agree to make sequestration cuts to our Department of Defense that threaten the readiness of our forces.”]

In the 1980s, Ronald Reagan could run up deficits to build up defense and still be hailed as a conservative icon. (Of course, defense wasn’t the only source of debt: Reagan also cut taxes, which failed to boost revenues as the famous supply-siders Laffer Curve predicted, while Democrats fought his plans to reduce domestic spending). Today, there are many Republicans who argue that excessive government spending in general and the national debt in particular are far greater threats to the United States than any foreign foe.

[Updated: Heritage’s James Carafano told me after Wednesday’s event that fiscal conservatism and a strong national defense are symbiotic, not opposed: “You have to move on all fronts together,” he argued. “You cannot fix defense without fixing the entitlement state” and all its escalating costs. But many members of his own party would argue we need to fix the deficit first, even at the price of defense].

“We’ve got to deal with that argument,” Talent acknowledged when I asked him about it Monday evening. “But really if you think it through,” he went on, “the argument from fiscal frugality works in our favor, not against us.”

How so? To begin with, Talent said – echoing many of the military’s top commanders – it’s far more cost-effective to keep ships, aircraft, and infantry units in fighting trim, with a regular cycle of maintenance and training, rather than to defer maintenance, cancel training, and have to fix the compounding problems later, as sequestration is now forcing the armed forces to do. It’s less expensive, in the long run, to do things the right way. Said Talent, “as a practical matter, if you allow the force to hollow which is what it’s doing right now, eventually we’re going to [have to] catch up, [and] it’s going to cost more money.”

In the final analysis, Talent and his collaborators add, there’s nothing more expensive – in money and in lives – than a war we weren’t strong enough to deter.

“The ebbing of American power, its absence, seems to us a terrible temptation to violence and conflict,” said Donnelly. “We see what the consequences of ‘leading from behind’ are, not just in the Middle East but in East Asia, and we don’t much like it. By contrast, the peace of Europe, the product of a century of American engagement and security commitment by presidents of both parties, looks pretty durable.”

That means, Sen. Talent said bluntly, “we have to spend a lot more money on defense… compared to what we’re now projected to spend.”

“We’re not arguing we shouldn’t cut waste out of the budget,” Talent went on. But all wings of the conservative movement, he said, “[even] libertarians… understand the core function of the government is the common defense.”

Defense against what with what, however, is a contentious question. Talent argued for a larger navy to safeguard America’s trade across the “global commons” and missile defenses to stop rogue states like North Korea and Iran. But, he said, “we don’t get into the specifics of what force structure ought to look like.”

In contrast to the Cold War, Talent said, “there isn’t any one threat , but there are a number of them that, I think, everybody agrees are a danger: Rogue states getting nuclear weapons, terrorism, the surge in Chinese power.”

The problem is that the Cold War consensus that Talent and company are trying to recreate depended on a bipartisan appreciation of the Soviet threat. To repurpose a phrase of Samuel Johnson’s, there’s nothing that concentrates the mind so marvelously as the prospect of being nuked.

It was still hard enough to get consensus on what to do about the Communists. There were bitter and often partisan debates over “Star Wars” missile defenses, Pershing missiles in Europe, aid to the Nicaraguan contras, and interventions from Korea and Vietnam to the Dominican Republic and Grenada. At least, though, the mainstream of American policymakers agreed the Communist bloc was a major danger. In the absence of such an overwhelming and obvious threat, America has a poor track record of formulating a sound strategy or investing in defense until the disaster is banging on our doors, as it did on December 7, 1941.

[Updated: You want to get people to wake up without having to have “a precipitating event” like a Pearl Harbor, former Senator Jon Kyl told me after Ayotte’s speech, which he had introduced. Figuring out how to do that is the purpose of both the AEI-Heritage project and a parallel “American Internationalism Project” he and former Sen. Joseph Lieberman are running, also out of AEI. Just last week, Kyl said, the internationalism group met with pollsters to better understand public attitudes: “If we can understand those appropriately,” he said, “and then begin to recast the arguments, which can no longer be expressed in Cold war terms to a generation didn’t experience the Cold War, I think we’ll find ways to do it – but it’s a real challenge.”]

So the “Project for the Common Defense” has a long hard road ahead of it. “We are clear-eyed about the need to grow this national security consensus in concentric circles,” said MacKenzie Eaglen, a member of the Breaking Defense Board of Contributors who once worked at Heritage and now works at AEI. “First, there is work to do in the conservative house to broaden our thinking and appeal within our own ranks. Then we must try to forge new relationships between conservatives and Blue Dog Democrats and beyond.”

“It’s true we don’t have a consensus about strategy, but that’s really because we haven’t tried to get one,” Talent argued. “With all due respect to the presidents since the Cold War years” – both Democrats and Republicans – “none of them has ever led a systematic discussion nationally about what America’s strategic mission in the world ought to be.”

Whatever strategy we do decide on, Talent added, we need adequate resources to execute it, which sequestered budgets won’t provide. “Our concern,” he said, “is that as our capabilities decline and as the force hollows, the strategy will necessarily fail, whatever tactical choices presidents make.”

[Or as Sen. Ayotte put it, “we do face a diminished capacity: No grand strategy can overcome that. We can have any grand strategy we want,” but without a well-funded force to execute it, “it’ll just be a stack of paper sitting on a desk that nobody uses.”]

Updated Wednesday June 26 at 5:30 pm.