So, let’s get this straight: Barely 6 percent of Americans even think their president should focus on foreign policy; Afghanistan's government badly needs continued U.S. help to hold off its enemies; yet President Hamid Karzai wants Washington to say sorry before he’ll allow U.S. troops to stay on in his country past 2014.

It’s tempting to say, not to put too fine a point on it, screw you.

The U.S. has already spent more than $640 billion in a 12-year war in Afghanistan. Over 2,000 American soldiers have died there. Thousands more have been injured, and perhaps tens of thousands have returned home carrying mental and emotional scars whose full toll may not become apparent for years. Osama bin Laden — the primary target of all this effort — has been dead for two-and-a-half years, and his terror organization is nearly so.

Karzai’s reported conditions for a long-term “status of forces agreement” that would allow a residual U.S. troop presence in Afghanistan include a letter of regret from President Barack Obama for past U.S. “mistakes” in the war, and a pledge that American soldiers won’t barge into Afghan homes except under extraordinary circumstances. Both demands address longstanding Afghan grievances, but they completely ignore the fact that many U.S. officials, let alone ordinary citizens, would happily take this opportunity to say goodbye and good riddance to Afghanistan, when U.S. forces withdraw next year.

The U.S. resorted to this “zero option” in Iraq nearly two years ago, after a similar disagreement over a long-term troops deal. While Iraqis have suffered grievously since then from continued bombings and shootings, most Americans have hardly noticed the difference.

Trained and armed by the U.S. and North Atlantic Treaty Organization, the Afghan Army is probably strong enough now to hold Kabul and the northern half of the country on its own. As for the possibility of an al-Qaeda resurgence inside Afghanistan, U.S. drone strikes have proven more effective in taking out individual bad guys than a massive, fixed troop presence.

The truth — obvious to most everyone outside the presidential palace in Kabul — is that Afghanistan needs the Americans far more than the reverse. Still, the U.S. does have a serious, continuing interest in Afghan stability, big enough that the White House should take the domestic political hit and get this deal done.

It’s worth remembering a couple things. First, if all U.S. troops — nearly 70 percent of the total international military presence — withdraw next year, none of their allies are likely to stay either. However well trained, Afghan forces will lose the ability to call in air strikes and airborne reinforcements and medevac rescues.

The Taliban have already ramped up the pace of their attacks this year, despite flirting with the idea of peace talks. They will have much less incentive to come to the table if they believe they’re likely to make substantial gains on the ground after 2014.

Second, the prospect of a full U.S. withdrawal could help the Taliban to raise funds in Pakistan and the Gulf, as supporters cheer on the warriors who rid Afghanistan of infidel invaders. Some in the Pakistani military and intelligence community might exploit the post-2014 vacuum to help allies — particularly the vicious Haqqani network — carve out zones of influence in the south and east of Afghanistan. That would not only undermine the authority of any government in Kabul, but create safe havens for anti-India militants eager to spark a conflict between South Asia’s nuclear-armed rivals.

Third, in Kabul, the various warlords and ethnic strongmen that dominate different parts of the country have only temporarily bought into an established political process. They’ve formed ethnically diverse slates of candidates for next year’s presidential elections, and are paying lip service to the need for a free and fair vote. The perks and privileges that have come with the billions of dollars that flooded Kabul in the last decade have kept them from infighting, but the aid and investment is likely to dry up in the event of a full Western withdrawal, not least because projects won’t be able to proceed without security. A shrinking pie will make it harder to paper over tensions and rivalries between the various armed factions.

Finally, while most Afghans can’t just pick up and leave with the Americans, some can — and they are the citizens the country can least afford to lose. Already there’s evidence that savings are flowing out of the country to safer havens. The small-but-vital Afghan middle class could well follow if they do not see a stable future at home.

Of course Afghans — including their mercurial president — should know all this better than anyone, and should be striving to make a deal on troops possible rather than throwing up roadblocks. But Washington is no stranger to self-destructive political grandstanding. We shouldn’t let Afghanistan’s blind us to our broader interests. Better to admit “regret” now than to suffer it in spades later.

(Nisid Hajari is a member of the Bloomberg View editorial board. Follow him on Twitter.)