After nearly two-and-a-half years of dithering, President Barack Obama finally seems poised to take action against the thuggish regime of Bashar Assad.When the Syrian military attacked rebel-held suburbs of Damascus last week with chemical weapons, killing hundreds of innocent people in what US Secretary of State John Kerry labeled a “moral obscenity,” Washington could no longer ignore calls that it intervene.Not since Saddam Hussein rained poison gas down on the Kurds of Halabja in northern Iraq in March 1988, has a Middle Eastern leader made such brazen use of chemical weapons against civilians.Allowing such an incident to go unpunished would clearly set a dangerous precedent, paving the way for rogue regimes around the world to employ fearful weapons with impunity. Hence, if and when the US and its allies do strike Syria, they deserve our full backing and support.But while international wrath has justifiably been aimed at Assad and his minions for their malevolent and indiscriminate slaughter, there is a troubling question related to this latest turn of events which few seem prepared to tackle: just how much responsibility does Obama himself bear for what happened? After all, by ignoring Assad’s previous atrocities, and even his use of chemical weapons earlier this year, didn’t the president’s inaction serve to encourage further escalation? Since March 2011, the dictator of Damascus has been waging a deliberate campaign of homicide against his opponents, be they real or imagined.Upholding his father’s lethal legacy, young Bashar has shown no compunction about slaughtering his own people in his attempt to crush the uprising against him.As a result, more than 100,000 Syrians have been killed and another two million have been turned into refugees since fighting flared between loyalists and opponents of the regime. This carnage was greeted with little more than hand-wringing by Washington, which found itself unwilling to become involved in another foreign entanglement, particularly one which pitted bad guys (Assad & co.) versus other bad guys (al-Qaida-dominated rebel groups).But it was Obama himself who then drew a line in the sand, clearly demarcating the ostensible limits of American patience.Recall that at a news conference back on August 20, 2012, Obama told reporters, “We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized.”That, the president insisted, “would change my calculus. That would change my equation.”Sure enough, eight months later, in April 2013, reports surfaced that Assad had used Sarin nerve gas against the rebels. The White House even issued a statement on April 25 saying that US intelligence believed “with varying degrees of confidence” that Syria had deployed chemical weapons on a “small scale.” The British Foreign Office went even further, declaring that, “Material from inside Syria tested positive for sarin.”Despite this unabashed crossing of his “red line,” Obama did nothing. He hemmed and hawed until the issue faded from public view. But Assad clearly got the message. He saw that his atrocious actions were met by American inaction. And clearly the Damascene despot understood that he could literally get away with mass murder.As Arizona Republican Sen. John McCain noted this week, “Assad was able to use chemical weapons before and there was no response, and so why not do it again?” “This should surprise no one,” McCain said, adding, “They viewed that not as a red line but as a green light, and they acted accordingly.”McCain has a point. In a world where many countries still look to the United States for leadership, what Washington chooses not to do is often as important as what it does. By electing to sit on the sidelines for months on end and failing to uphold his own “red line,” Obama projected weakness and a lack of will, which Assad interpreted as a license to pull the trigger. The inescapable conclusion to be drawn is that the current crisis is a direct result both of Assad’s action and Obama’s impotence.At this point, the question of whether to strike Damascus is no longer just about Syrian chemicals. It is about American credibility and whether the sole remaining superpower still has the moxie to stand by its word and maintain and preserve global order.I don’t envy the position in which Obama now finds himself or the choices he is being forced to make. But as the leader of the free world grapples with how to react, he should take a moment to consider just how much it was his own failings which gave rise to our present predicament.