Last Updated 3:08 p.m. ET
(CBS) WASHINGTON - Sen. John McCain today called for the United States to lead an "international effort" involving air strikes on Syria's military forces.
"After a year of bloodshed, the crisis in Syria has reached a decisive moment," McCain, R-Ariz., said in a speech to the Senate Monday afternoon.
"The kinds of mass atrocities that NATO intervened in Libya to prevent in Benghazi are now a reality in Homs. Indeed, Syria today is the scene of some of the worst state-sponsored violence since Milosevic's war crimes in the Balkans, or Russia's annihilation of the Chechen city of Grozny."
He said the U.S. has a clear national security interest defeating Syrian president Bashar Assad.
McCain said that other foreign powers will step up militarily against Assad. "Some kind of intervention will happen, with us or without us," he said. "The real question for U.S. policy is whether we will participate in this next phase of the conflict in Syria, and thereby increase our ability to shape an outcome that is beneficial to the Syrian people, and to us."
McCain said President Obama has made it the objective of the United States to end the killing in Syria. "He has committed the prestige and credibility of our nation to that goal, and it is the right goal.
"However, it is not clear that the present policy can succeed. If Assad manages to cling to power - or even if he manages to sustain his slaughter for months to come, with all of the human and geopolitical costs that entails - it would be a strategic and moral defeat for the United States. We cannot, we must not, allow this to happen."
"For this reason, the time has come for a new policy."
McCain charged the Obama administration with "hedging its bets" on Assad - assuming that he will fall without having to commit military support to his downfall.
"As we continue to isolate Assad diplomatically and economically, we should work with our closest friends and allies to support opposition groups inside Syria, both political and military, to help them organize themselves into a more cohesive and effective force that can put an end to the bloodshed and force Assad and his loyalists to leave power. Rather than closing off the prospects for some kind of a negotiated transition that is acceptable to the Syrian opposition, foreign military intervention is now the necessary factor to reinforce this option. Assad needs to know that he will not win.
"Providing military assistance to the Free Syrian Army and other opposition groups is necessary, but at this late hour, that alone will not be sufficient to stop the slaughter and save innocent lives," McCain said. "The only realistic way to do so is with foreign air power . . .
"Therefore, at the request of the Syrian National Council, the Free Syrian Army, and Local Coordinating Committees inside the country, the United States should lead an international effort to protect key population centers in Syria, especially in the north, through airstrikes on Assad's forces. To be clear: This will require the United States to suppress enemy air defenses in at least part of the country."
Full remarks by Sen. John McCain on Syria (senate.gov)
McCain said the ultimate goal of airstrikes should be to establish and defend safe havens in the country where opposition forces can organize and plan their anti-Assad activities, and where humanitarian and military assistance could be delivered.
When talking about the potential drawbacks of engaging militarily in the conflict, McCain said the risks of sectarian conflict in Syria would exist whether the U.S. gets involved or not, and that it is to America's benefit that we do so, particularly with establishing trust with anti-Assad forces.
"We should not overstate the potential influence we could gain with opposition groups inside Syria, but it will only diminish the longer we wait to offer them meaningful support," he said. "And what we can say for certain is that we will have no influence whatsoever with these people if they feel we abandoned them."
He also responded to fears that the U.S. should contribute to the militarization of the conflict. "If only Russia and Iran shared that sentiment," McCain said. "Instead, they are shamelessly fueling Assad's killing machine. We need to deal with reality as it is, not as we wish it to be - and the reality in Syria today is largely a one-sided fight where the aggressors are not lacking for military means and zeal. Indeed, Assad appears to be fully committed to crushing the opposition at all costs. Iran and Russia appear to be fully committed to helping him do it."
"Who do we want to win in Syria - our friends, or our enemies?"
The senator urged action to end the bloodshed as soon as possible. "Time favors the hardliners in a conflict like this," he said.