What is the most urgent foreign policy challenge facing President-elect Obama as he prepares to take over the reins of power? How to stop Iran from building an atomic bomb? How to withdraw from Iraq? How to defeat the Taliban offensive in Afghanistan? How to respond to threats from a resurgent Russia?

Answer: It is all of these, because they are all linked in one way or another, except perhaps for Afghanistan, which may be a war America cannot win and eventually will abandon (more about that at a later date). If the new president puts a foot wrong in any one of these foreign policy crises – say, Iran or Russia – that could have devastating consequences in other areas – Iraq, for example.

Let me explain. Mr. Obama needs to find a way to honor his campaign pledge to pull combat troops out of Iraq within 16 months. He has already given himself some wiggle room by stating that he will consult with the Iraqi government and U.S. commanders on the ground before making any decisions. But we can assume he wants the troops out as soon as possible. The only way to do that without simply handing over Iraq to Iran on a platter is to make a deal with Iran. His administration needs to talk with Iranian decision makers, and he has indicated a willingness to do so. The Iranians are also ready to talk. Hard-line Iranian officials, including President Mahmoud Ahmadinejad, publicly congratulated the president-elect on his victory. The Iranians haven't done that since the United States broke relations with them 30 years ago.

What kind of a deal could the United States make with Iran? Both sides could agree to political arrangements that neither side would prefer, but which would leave Iraq with a government that is neither pro-American nor pro-Iranian.

What could the US offer Iran to induce it to give up its goal of becoming the hegemon of the Persian Gulf? Any deal would have to include guarantees that Iraq will no longer threaten Iranian security (as it did in the 1980s) and that the U.S. will abandon its goal of regime change in Iran.

What could Iran offer in return? Most importantly, it could agree to international controls to reduce the likelihood that its nuclear power program would be used to produce nuclear weapons. Some experts believe the Iranian regime has intended all along to use its nuclear program as a bargaining chip.

Could something like this be in the works? Possibly. The Israelis have dialed back their rhetoric. They now say that Iran is two to five years away from producing a nuclear weapon, reducing the immediate threat of an Israeli air strike on Iran's facilities. And the Bush administration, after employing threats, bluffs and sanctions to get Iran to budge on the nuclear issue, has recently gone quiet on Iran. There are even rumors that Washington is thinking again about establishing low-level diplomatic relations with Tehran, an idea that administration officials floated last summer but that went away after the Russians fought with the Georgians in South Ossetia.

That brings us to Russia, another player in this multi-dimensional game.

Since the brief war in South Ossetia, tension has increased sharply between the U.S. and Russia. Both have been playing tit for tat. Washington is provocatively pushing ahead with plans to install American anti-missile bases on Russia's borders. Russia has responded by announcing it will install short range missiles in Kaliningrad on NATO's borders. But what must worry Washington most are Russian hints that it might sell weapons to Iran. One way to defuse that threat would be to seek a compromise with Russia on the issue of the American bases, perhaps offering to include them in a joint Russian-NATO anti-missile system. It would be easier for the United States to reach a deal with Iran over the future of Iraq, if Russia is cooperating rather than playing games.

Mr. Obama will face extraordinary and highly complex challenges abroad from the day he takes office.
One way President Bush could ease the way for a smooth transition would be to go ahead and establish some form of diplomatic relations with Iran before he leaves office. That would take the political curse off the move and help a new and unproven president who will be under fire from the Republican right if he appears weak when faced with foreign threats. Lord knows, Mr. Obama will need all the help he can get.