The US policy in Yemen really has been breathtakingly bad. In the Arab Spring, Obama basically abandoned many of the US's traditional allies in the region, preferring to sit back and watch. In Yemen, when things settled, a very weak leadership remained and Obama and the US used that leadership to conduct multiple drone strikes throughout Yemen, angering many of the citizens of Yemen against both the Yemeni leadership as well as the US. This was allowed to escalate, turning large parts of the country over to terrorists and resistance, egged on by Iran and now the whole leadership/government structure in Yemen has collapsed.
I used to think that the world could survive the remainder of the disastrous Obama administration but that's becoming iffy. It seems quite laughable now that many in the US saw GW Bush as a problem in that region of the world - the absence of strong American leadership is a terrible price this region is paying.