The third front in Afghanistan: the American public

Recent polls show that a majority of Americans believe the war in Afghanistan is not worth fighting. This is said to weigh heavily on President Obama as he considers Gen. Stanley McChrystal's request to focus on counterinsurgency and add 40,000 troops to the field.

Ideally, when leaders deliberate over a proposed foreign policy, they consider whether it furthers the national interest, not whether the public supports it at the moment. A paradox of US democracy is that people expect their officials to ignore them from time to time.

Leaders generally depend on two assumptions when making foreign-policy decisions: (1) that the public will support what emerges as good policy over the long term, and (2) that a foreign policy's effectiveness is divorced from domestic public support.

Under normal circumstances, the public could expect Mr. Obama to focus only on the question of whether the war's goals are worth its costs, ignoring the transitory polls.

The situation in Afghanistan, however, throws this model out the window. Today, the American public is the newest front in winning the conflict in Afghanistan.

Obama's consideration of public opinion shows that the administration recognizes that the public might not support even a successful long-term effort, and this lack of support might doom an otherwise effective mission.

What are some of the reasons for lagging support?

Because the war's goals are vague and abstract (e.g., building democracy and stability) and difficult to measure (e.g., making terrorism less likely), the public might deem any long-term mission obscure and wasteful – even an effective one.

It is also possible that the public is able to comprehend and measure the goals, but disagrees with the president that they are achievable or worthy enough. Or it may simply be that Americans are worn out – tired of sending soldiers to fight and tired of spending billions in faraway lands to liberate people who do not want us there entirely.

The nature of the war's goals makes it difficult to maintain public support – a point to be considered before entering into such conflicts in the future.

No matter the reasons for declining support, it seems a president should ignore public opinion to execute a necessary war – a term Obama applies to the Afghanistan conflict. In Afghanistan however, the viability of any counterinsurgency strategy depends upon continued support from the American public.

The US government must convince our existing and would-be Afghan allies that US commitment to developing a stable nation is resolute. Among the Iraqi Sunnis, Washington won allies not by being friendly, but by convincing them that US-Iraqi interests dovetailed and that the US was committed to and capable of winning.

Washington will see no such parallel in Afghanistan if Afghans believe US troops leaving early is likely. But if public opinion stays negative, Afghans may be justified in their skepticism.

American leaders can resist the public's wishes for only so long. If the public continues to oppose the effort in Afghanistan, the US may have to pull out early – even if the counterinsurgency is working.

This is crucial, because under a counterinsurgency strategy Afghanistan is either worth fighting until our goals are achieved, no matter how long it takes, or not worth fighting at all. A middle ground – where the US spends billions more, American soldiers and Afghan civilians continue to die, and we place yet more credibility on the line, only to leave early and have the Taliban return to power – would be worse than if the US pulled out in the first place.

For these reasons, when Obama analyzes McChrystal's plan he needs to consider not only if it would work had he five to 10 years of steady support, but also – despite the vague nature of some of the goals – whether it will deliver results tangible enough to convince a weary public to provide that very support.

Should he choose prolonged escalation, Obama has to walk a fine line between managing and raising expectations. While telling the truth, he needs to raise expectations so people believe the goals are worth the costs. But he needs to manage expectations so people won't lose faith if the strategy doesn't deliver immediately.

He needs to make the public aware of the absurdity of nation-building on two and four-year election-cycle time frames. It took America 12 years to replace the unworkable Articles of Confederation with the Constitution. Americans seem to forget that when we complain about the lack of progress in Iraq or Afghanistan.

After eight years of war, there are now three fronts in the conflict against the Taliban, Al Qaeda, and associated regional movements, commonly called "AfPak."

The first is in Afghanistan. The second is in Pakistan. And the third is in America, where the public needs to maintain a high enough level of support for our commitment to the Afghan people to have credibility and sufficient longevity.

It is now the age of "AfPakAm."

Jacob Bronsther, a law student at New York University and former Fulbright scholar, writes for ThePublicPhilosopher.com. Shalev Roisman, a Harvard Law School graduate, recently completed a clerkship on the Second Circuit Court of Appeals in New York City.