While the Iraqi military, with some help from Iran and the U.S., may be able to hold on to what is left within its purview, it's hard to see it reclaiming much territory without major foreign interventions. Which could easily backfire, both for Tehran and Washington, the only capitals which might be involved.
Political differences need to be resolved through an inclusive process within Iraq with the active support of regional players. Neither the region nor the world can afford to underestimate how dangerous the present situation in Iraq has become, virtually overnight, and how vital it is to contain and reverse this threat.
Everything depends on whether Tehran, and not just President Hassan Rouhani, is serious. No surprise, many analysts -- and more importantly, paladins of Capitol Hill -- remain skeptical. And that doubt has fueled efforts to impose new sanctions, which would impede if not kill efforts to reach a final accord.