I don't doubt that Assad is far more rational and responsible than ISIS, that much is clear to anyone. Under the Assad dynasty, Syria was at the very least a functioning country.
From a point of political convenience it might seem like Assad is the best bet in Syria, and no doubt most people would be happy to return Syria to its pre-Arab Spring ways if that was possible. Under Assad, Syria would be far less of a threat to global security.
But to imagine that we can return to those days is an illusion. The truth is that the Assad regime bears the most responsibility for the situation in Syria. First, by virtue of keeping Syria an authoritarian police state for four decades, and refusing any meaningful reform. When he gained power, many in the West hoped that Assad Jr. would be a moderate that would modernize and liberalize his country. Those hopes were dashed, either through Assad's lack of willingness or lack of courage. His response to the initial protests paved the way for this civil war, and his unwillingness to step down continued it. Mubarak at least had the decency of resigning after three weeks.
The Assad regime is responsible for roughly 200,000 of the 300,000 deaths in Syria (along with his allies, Iran and Hizbullah, who participate directly in the fighting). The regime has killed and tortured far more Syrians than ISIS. Most displaced Syrians were displaced by the actions of the national Syrian Army, not the actions of rebel groups, extremist or otherwise. The regime used siege and famine as weapons, starving rebel strongholds to submission, including the large Al-Yarmuk Palestinian refugee camp near Damascus. Assad used chemical weapons against civilians in his own capital. I think this sentence needs to be read more than once to be fully appreciated. If I could go back in time and tell people that in 2012, a dictator used weapons of mass destruction in his own freaking capital against civilians, and that many people would later consider him a viable partner for diplomatic efforts in the region, I would have been laughed at.
The Sunni population of Syria will never accept Assad as their ruler, and for good reason. He killed their sons and daughters, he tortured them, he gassed them, he starved them, he oppressed them. This is why the rebellion has gone on for so long despite the efforts of four highly trained military forces fighting against the rebels: the Syrian army, Hizbullah, Iran's Revolutionary Guard and now Russia.
It's not about the 'devil we know', or the unpalatable realities of global politics. This is a ruler that has zero legitimacy with the majority in his country, and importantly, the majority on whom groups like ISIS rely on for support . The military chief quoted here is, in my opinion, very wrong. You cannot defeat ISIS by keeping Assad in power, the hatred towards him is the main engine driving the growth and influence of ISIS. And it's also morally repugnant.
