When President Obama sent US military forces into Libya in the spring of 2011 for a war that was supposed to last "days, not weeks," there were major problems. Central to these problems, was the fact that he did not seek congressional approval before entering into war. This is what Obama criticized, when he was a candidate, President George W. Bush for doing.
Now that China and Russia have vetoed UN sanctions against Assad's government and the Syrian opposition has announced they're fighting for victory instead of attrition, Obama appears ready to bypass Congress again and unilaterally send military personnel into Syria in support of the opposition.
According to a report in the New York Times, Obama has abandoned diplomacy and is instead going Senator John McCain's way: sending aid to the Syrian opposition and trying to rally other countries to join the US in toppling Assad. In this report, the administration claims it will not be sending arms to the Syrian opposition, only financial assistance, "communications training and equipment."
In other words, we could soon be looking at Libya all over again.