Those who complain about the absence of bipartisanship in the nation’s capital are sorely mistaken. When it comes to caving to a powerful constituency and bestowing benefits, bipartisanship is flourishing.

Today’s exhibit: military pensions.

Just two months ago, both houses of Congress overwhelmingly passed, and the president signed, a budget deal. All the parties involved happily patted themselves on the back for a display of cooperation and fiscal responsibility. The deal included savings of $7 billion over 10 years by reducing cost-of-living adjustments for working-age military retirees.

That’s reducing, by one percentage point, not eliminating as the Simpson-Bowles commission recommended. That’s working-age retirees — those under 62 who have served 20 years (fewer than one in five make it that long) and, presumably, have taken civilian jobs.

On average, enlisted members begin collecting retirement benefits in their early 40s, meaning that many veterans will spend more years collecting benefits than they did serving. At age 62, benefits are bumped back up so that veterans receive full inflation protection.

House Budget Committee Chairman Paul Ryan explained the thinking in a December interview with the Weekly Standard. “We give them a slightly smaller adjustment for inflation because they’re still in their working years and in most cases earning another paycheck,” the Wisconsin Republican said. “Our goal here is to make sure that no other country comes close to matching the U.S. military, and the stress on the budget in the future brings that whole entire notion into question.”

That was December, this is February. Veterans are in an uproar. Nothing concentrates the congressional mind like a powerful interest group (veterans today, seniors tomorrow) complaining about cuts.

Thus, the only debate over the change was how quickly it would be undone and whether that change would be offset by other cuts. The House voted overwhelmingly Tuesday to restore full benefits, “paid for” by requiring additional, unspecified cuts to Medicare and other entitlement programs — in 2024. The Senate is poised to follow suit, with the only area of disagreement the question of whether and how to pay for the change.

Meanwhile, proving that cowardice is not confined to one end of Pennsylvania Avenue, White House economic adviser Gene Sperling, at a breakfast sponsored by the Christian Science Monitor Tuesday, said that President Obama supports reversing the cuts he signed into law, at least for current recipients.

Of course veterans deserve generous retirement pay. Yet the current system is extraordinarily generous compared to private-sector programs. A Congressional Research Service report found that the cost-of-living change would mean a loss of $69,000 in benefits for the average enlisted person and $87,000 for the average officer. Significant, but that is out of lifetime benefits of $1.73 million and $3.83 million, respectively.

Meanwhile, as four senior retired military officers pointed out in a statement issued by the Bipartisan Policy Center, Military personnel costs have doubled since 2000, even as the active-duty force has shrunk by 10 percent.

“Such cost growth is unsustainable, and the leadership of the Army, Navy, Air Force and Marines all agree that the costs of benefits for personnel are starting to crowd out other important investments that support training, readiness and modernization,” the officers said. “This plan is an important first step in tackling those costs.”

Or was. The issue, unsurprisingly, has been distilled to its political essence. “You vote yes, you’re for our vets,” Alaska Democrat Mark Begich said on the Senate floor Tuesday. “You vote no, you’re against our vets.” Well, if you put it that way. . . .

There are lessons to be gleaned from this depressing episode, with its predictable denouement. The most obvious involves politicians of both parties who are happy to proclaim their willingness to make hard choices — and cowardly about actually standing by them. Especially in an election year, brave lawmakers are an endangered species.

A more sophisticated corollary is the difficulty of applying budgetary pain in a piecemeal manner. Sacrifice is more palatable when shared. The retirement change, Maya MacGuineas of the Committee for a Responsible Federal Budget told me, “is a provision that I don’t think would have gotten a second look if it was part of a big package.”

But of course the appetite for such a package is as lacking as the capacity to achieve it. Hence the race to repeal the military retirement provision, setting a land-speed record for bipartisan fecklessness.

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