CNN Global Public Square Editor's Note: Barack Obama has won reelection as America’s president. But while the economy – and avoiding the so-called fiscal cliff – will inevitably take up much of his time, there are numerous foreign policy challenges facing the next administration. GPS asked 10 leading foreign policy analysts to name 10 things that Obama should focus on next. The views expressed are, of course, the authors' own.

There are two top priorities in national security for Barack Obama as he enters his second term.  The first is Iran, the second the return of al Qaeda.  Of course, there are pressing challenges everywhere; the Middle East is in the process of a generational transformation that will in the short term look much worse for America’s interests, allies and values.  China’s strategic ambitions are increasingly and obvious anathema to our and our allies’ interests in the Pacific.  A rapid exit will be failure in Afghanistan.

But these are slow motion train wrecks.  The two oncoming locomotives are a nuclear weapon and the means to deliver it in the hands of one of the rashest and most dangerous regimes in the world; and the metastases of al Qaeda and its cohort from South Asia to the broader Middle East to the horn of Africa and beyond. Iran now has enough nuclear material, enrichable in short order from 20 percent, to fuel several nuclear weapons.  Regime leaders have expressed the intention of dominating their region and destroying Israel.  We ignore those threats at our peril.  Al Qaeda now controls substantial and growing territory around the world, and will make impressive gains in Iraq, Syria and Egypt (Sinai) before long.  For the last four years, Barack Obama has allowed these problems to grow.  There is a crisis around the corner, and much must be done to avert it.