In Baghdad, representatives from the six global powers (the five permanent members of the UN Security Council plus Germany) are in the middle of discussions with Iran over its nuclear program. Initial reports have been positive: Iran indicated to the IAEA that it is willing to allow the agency to inspect some of its secret installations. And while Western diplomats do not expect the Baghdad meeting to provoke an immediate breakthrough, optimism abounds that the talks will lay the foundation for definitive progress in the coming months.The news looks good right now, but there are many reasons to think it will only get trickier from here.First, it takes enormous diplomatic skill and effort to hold together a coalition as diverse and unwieldy as the U.S., China, Russia, Germany, France, and the UK (not to mention the EU, which is imposing its own embargo on Iranian oil effective July 1). So far, the coalition has held firm. But agreeing to hold talks is a far cry from agreeing to concrete action. Iran understands that its best play is to fracture the coalition, and it will do everything possible to pry the partners away from each other.Second, the global powers have to strike a delicate balance when it comes to calibrating the strength of the sanctions. The world economy remains on edge, and while sanctions obviously need to be tight enough to hurt Iran’s oil exports, they cannot be so tight as to tip the teetering world economy into recession. Thankfully, the G-8 vowed this week to steady world oil supplies, even as sanctions tighten on Iran, to ensure the price of oil does not skyrocket.And finally, there’s Israel. No country has a greater stake in these discussions than Israel. While it has refrained from military action so far, the global powers need to balance their diplomatic commitments to Iran with the need to maintain Israeli confidence in the process.