The landmark deal last week between Secretary of State John Kerry and his Russian counterpart Sergei Lavrov is, in many ways, a major breakthrough. It may well save lives. Against the backdrop of what has been the worst war of the 21st century, that’s a prize worth seizing. The problem: The effects will be strictly limited. The agreement is really several significant, but limited, tactical deals – on aid, on local ceasefires and on coordination against certain Islamist groups that both Washington and Moscow don’t want to see as part of the long-term future of Syria. That’s something, to be sure. To get that deal, however, Kerry and Lavrov appear to have deliberately avoided the toughest issues. Most crucial, the ultimate fate of Syrian President Bashar al-Assad was off the table. That omission has likely been noticed in Damascus, Aleppo and the various regional capitals that must also help decide the conflict. It’s hardly surprising the United States and Russia can’t agree. Not least because there is still little to no agreement in Washington on exactly what the United States should be doing. Nor are European capitals – many increasingly worried about the political implications of the growing flow of refugees in their countries – all singing from the same song book. Some would like the war over at any cost. Others are still looking for specific outcomes. In the United States, for example, some in the State Department have called for Washington take deliberate military action against the forces supporting the Assad regime. It’s not that the department necessarily believes that Assad can be defeated. But they believe his actions over the last five years – including chemical attacks in the last month or so – demand a more punitive response. Others, including a range of liberal and neoconservative voices see that approach as unrealistic. Further degrading the government’s ability to maintain control, they insist, only worsens an already grim situation and makes long-term rebuilding in Syria even harder – whether under a new government or Assad. Washington is unlikely to resolve this issue before the presidential election in November. Whoever wins will have to come up with a strategy that factors in what happens in Syria until then – including where things stand militarily, particularly in Aleppo. That’s where the joint US-Russian coordination against Islamist groups will likely have real impact. It makes sense on many levels. First, most of the international and regional powers – as well as many local forces – are effectively on the same side. They want Islamic State gone – although what will replace it is obviously a more contentious issue. Peter Apps is Reuters global affairs columnist, writing on international affairs, globalization, conflict and other issues