LISTENING TO the last presidential debate, you’d think the only foreign policy issues President Obama and Mitt Romney have to discuss is when the word “terror” was first used to describe the attack on the Benghazi consulate and which man has invested more money in China. In fact, within months the occupier of the White House will have critical decisions to make on entirely different issues, from Afghanistan and Iran to Syria. We’d like to believe Monday’s debate will force the candidates to talk about some of those choices.

Fortunately, moderator Bob Schieffer has selected five topics that could prompt some specifics. The first, after “America’s role in the world,” is on Afghanistan and Pakistan — where both candidates have been unsatisfactorily vague. Shortly after the election, the U.S. commander in Afghanistan will send the White House his recommendation for how many of the 68,000 remaining U.S. troops, if any, should be withdrawn in 2013. While Mr. Romney and Mr. Obama have said they would stick to a NATO plan to withdraw all combat forces by the end of 2014, neither has said whether he would order significant withdrawals next year.

At the vice presidential debate, the most categorical statement by Vice President Biden was: “We are leaving [Afghanistan] in 2014. Period.” That raised the question of whether the administration is still committed to reaching agreement with the Afghan government on a “residual force” of trainers and counterterrorism troops that, by most estimates, would number in the thousands. Does Mr. Obama intend to drop that plan? And would Mr. Romney support a stay-on force?

On “red lines” for Iran’s nuclear program, the next subject on Mr. Schieffer’s list, Mr. Romney has at least a theoretical difference with the president: He says that he would not allow Iran to acquire the “capability” to build a bomb, a stricter standard than Mr. Obama’s vow to prevent the actual construction of the weapon. But Mr. Romney has played down the possibility of military action and has proposed measures — such as stricter sanctions — similar to those of Mr. Obama. What should be clarified is whether he would take military steps — or support an attack by Israel — to disrupt Iran’s capabilities even if there were no evidence it was trying to produce a bomb.

The two planned segments on “the changing Middle East and the new face of terrorism” should give the candidates plenty of time to debate the Benghazi attack. But Mr. Schieffer should push the discussion toward other subjects — beginning with Syria, whose civil war is threatening to become a strategic disaster for the region’s moderate forces and where neither candidate is suggesting consequential U.S. action. If the United States ends up intervening in Syria or Iran next year, or withdrawing in haste from Afghanistan, Americans should not have to ask themselves why there was no discussion of it before the election.