Secretary of State John Kerry SAUL LOEB/AFP/Getty Images

CLOSE TO A CEASE FIRE: The United States and Russia have the outlines of a ceasefire agreement in place, and if they can agree on the final details, a cessation of hostilities over Syria could start in just a few days. But the lingering issues are serious: How would a ceasefire be enforced? And what are the consequences of breaching it?

Instituting a temporary ceasefire has become a crucial component to sustaining foundering talks to bring the Syrian civil conflict to a resolution, as bombardments from the air and sieges on the ground are increasing the civilian casualty count – not to mention worsening starvation conditions in some places. But ensuring a ceasefire works will take a lot more than a handshake between President Obama and Russian President Vladimir Putin. Russia is going to be responsible for making sure the Syrian government, Iran, and their allies on the ground comply with the terms, while the United States is going to be responsible for holding the major opposition groups in line. But total agreement even within those camps remains elusive.

EUROPEAN UNION EXIT?: London’s mayor threw his weight behind a campaign to get the United Kingdom out of the European Union, a move that could have major consequences for the British as well as the rest of Europe. The U.K. is headed toward a likely referendum on the question of its E.U. membership in June, and all its politicians are weighing in. Prime Minister David Cameron supports staying.

The U.K. has never fully taken on the mantle of the E.U., staying out of the euro zone and the Schengen area, which allows people to travel between member nations without passport checks. Still, the departure of a member state with as much international heft as the U.K. at a time when Europe is dealing with currency woes, debt crises, and a major wave of refugee arrivals is a hit the E.U. might not be able to take.

ARMING THE KURDS: It’s become a popular refrain on the campaign trail, in Congress, and in almost every conversation involving the question of what to do next in the war against the Islamic State. As a rallying cry, it can also send nervous shivers down the spines of strategic planners, over what reaction actually arming the Kurds might produce from allies in Turkey and Iraq. As simple as it sounds, “arming the Kurds” is actually much more complicated than it sounds.

Keep this explainer handy as a reference, then, as the debate continues and expands, to remember how “the Kurds” are a variegated group, often splintered across national boundaries and ideological divisions.