During the political campaign President Obama repeatedly said  Afghanistan is the true central front in the “war on terror.”

He said he would commit additional troops (on top of 36,000 U.S. troops already there) to root out Taliban, al-Qaida and insurgent forces operating in the southern part of Afghanistan and in relatively safe havens across the border in parts of Pakistan where the central government has no effective control.

There is talk of an additional 30,000 U.S. troops, although it is unlikely that more than 10,000 or 12,000 will get there by summer.

In testimony before the Senate Armed Services Committee last week, Defense Secretary Robert Gates described the war in Afghanistan as “a long slog” in which it would be necessary to scale back U.S. objectives in that country, focusing on military activity and leaving “nation-building” activities to our NATO allies.

One wonders just how central this war is to core U.S. interests.

After seven years of hard slogging, conditions have improved in Iraq, in part due to the U.S. “surge” in numbers of troops and different tactics, in part due to developments like the Sunni “awakening” that began before the surge, and in part due to general war-weariness. But Afghanistan, where conditions have been deteriorating (roadside attacks and suicide bombings are up 40 percent over last year), challenges are more formidable.

Afghanistan is larger than Iraq, has a larger population (32 million to 27 million) and has a much more challenging, largely mountainous terrain. Whereas Iraq is rather urbanized, Afghanistan is largely rural. Afghanistan has never had an effective central government; the current Western-installed government has little effective control outside the capital of Kabul and is deeply corrupt. The largest cash crop by far is opium and the Taliban and other insurgents finance operations largely through heroin smuggling.

No wonder Afghanistan is the graveyard of empires, as the British discovered in the 19th century and the Soviets learned in the 1980s.

Almost all supplies for U.S. and NATO troops in Afghanistan come from two roads through Pakistan that are often harassed by insurgents and sometimes closed down by the Pakistani government. Gen. David Petraeus, who heads the U.S. Central Command, with responsibility for Central and Southern Asia as well as the Middle East, recently traveled to Kazakhstan to negotiate a supply route through that country. Establishing such a route, however, would require cooperation from Russia, with which U.S. relations are hardly warm, and which would want concessions the U.S. might be reluctant to grant.

In short, as Gen. Petraeus recently told Foreign Policy magazine, Afghanistan is likely to be the longest campaign in the long war on jihadist terrorism. Success is hard to define and will be even harder to achieve.

Thus it is legitimate to wonder whether it’s a good idea to commit more troops to a country in which almost the only point of agreement is resentment of foreign troops, to use the military to achieve what Gen. Petraeus and virtually all other authorities agree must lead to a political solution — especially after seven long years of sometimes desultory combat in Iraq.

There is little question al-Qaida, operating both in Afghanistan and Pakistan, is a threat. Whether it can be defeated militarily is another matter.

Would it be possible to let the Afghans run Afghanistan with the understanding the U.S. might sometimes use air warfare and special forces against al-Qaida forces without having tens of thousands of troops in Afghanistan? We hope that is an option President Obama is ready to consider.