As 2011 draws to a close, how fitting that Congress is fighting over money — again. Late Wednesday, a push to extend a payroll-tax break and unemployment benefits stood in the way of a crucial budget bill to fund the government’s operations. Demo-crats wanted to cover the cost of those initiatives with tax increases, Republicans with spending cuts.

In their rush to head home for the holidays, members of neither party want to discuss how continuing this year’s cut in the payroll tax and extending long-term jobless pay would add to our already enormous national debt. Here’s why: The payroll taxes that otherwise would be paid into Social Security only would be recouped years later, and that’s under the most optimistic scenarios. Illinois Republican Sen. Mark Kirk told the Chicago Tribune editorial board Wednesday that both parties’ proposals would add to U.S. borrowing — and move up the date when the most recent federal debt limit is exceeded.

Kirk’s main concern: Social Security already is imperiled — unable to properly benefit future generations unless it is reformed. Maybe a one-year cut in the payroll tax for 2011 made some sense. But continuing to cheat the program of the routine revenues on which it is structured inevitably endangers its ability to meet its obligations. And filling any shortfall in these Social Security revenues by borrowing still more billions is beyond foolhardy. It’s also the same sort of we’ll-gladly-pay-later-for-entitlement-spending-today that has put many nations of Europe in severe debt crises.

The dispute over the payroll-tax bill is claiming most of the headlines, but it’s only part of the pre-Christmas puzzle:

Both parties reached an agreement last week on the roughly $1 trillion spending bill, but Senate Democrats, urged on by President Obama, won’t pass it. They want to pressure House Republicans to accept, yes, the Democratic version of the payroll-tax cut. In this exchange of playground belligerence, Republicans have accused Democrats of holding the budget bill hostage, thus risking that ol’ debbil, a government shutdown. And Democrats have accused Republicans of trying to finagle a spending bill, then skip town for the holidays without negotiating a compromise payroll-tax cut.

So far, in other words, nothing constructive at either end of Pennsylvania Avenue. Just a lot of squabbling — and a dangerous perception from members of both parties that Americans can continue to underfund Social Security.

Any deal that invites more federal borrowing is a luxury the United States cannot afford. It would, though, fit Washington’s pattern of refusing to get a grip on the dangerous nexus of spending and debt.

All year long, the nation’s leaders have squandered opportunities to begin taming that debt. While they’ve bickered, the national debt has surpassed $15 trillion. Beyond Social Security, obligations for Medicare and Medicaid continue to threaten those systems as well. And additional cuts loom for the nation’s credit rating, in the aftermath of a historic downgrade from one rating agency in August.

The problems are urgent, the solutions evident but unable to gain any traction in Congress and the White House. The president’s Simpson-Bowles deficit commission, the Senate’s Gang of Six, the congressional supercommittee — oodles of good ideas, but no reconciling the federal government’s unsustainable spending with its insufficient revenues.

Gutsy leadership? Willingness to lose political advantage? Willingness to lose elections?

Nah. Instead of statesmanship, we get gamesmanship, brinkmanship and one-upmanship.

Plus the very real threat of an extended tax cut that will only shortchange Social Security and worsen our debt.