Cautious and unimaginative leaders never create such chances. And while they may avoid catastrophes like the Iraq invasion, they also open the door to unintended consequences that actually make their situations materially worse. (Even if they were not the authors of the problems they created, even if they could not solve them single-handedly, and even if it would be better, more just, or reasonable that someone else took the lead.) Further, and sometimes through repeated application of the same brand of caution, they compound their errors. Getting out of Iraq too quickly helped foster the conditions that led to the creation of the Islamic State, as did the failure of the United States to act — or to effectively lead a collation in acting — in Syria. Coming to the fight against the Islamic State too late and half-heartedly when we did has not helped. The chaos in Syria and Iraq has now profoundly impacted Turkey, Lebanon, Jordan, and indeed everywhere that the Islamic State has sewed its poisonous seeds. And it has empowered Iran greatly.

As a result, even a well-intentioned, potentially positive step like the Iran deal — when placed in the context of a region in turmoil — can have profoundly negative consequences if it upsets the regional balance of power. It further makes already apprehensive neighbors more apprehensive and can trigger actions among those states predicated on growing anxiety (that we played a role in exacerbating), among other things.

History, the war in Iraq, and countless other factors have brought the Middle East to where it is today. But what is also quite clear is that, in conjunction with those things, the abrogation by the world’s leading power of its leadership responsibilities has contributed to the contemporary tragedy we are witnessing. Moreover — and more importantly — it is setting the stage for a future in which future U.S. leaders may be asked to take risks far greater than those Obama sidestepped in order to contain the cascading consequences of his inaction, inexperience, and his overabundance of caution.