The crisis in Syria should remind us of three important truths: (1) if the prevailing rule is anything goes, pretty soon anything does; (2) rules have little impact unless someone is willing and able to enforce them; and (3) predators are more likely to strike when they sense weakness and vulnerability.
The raw acts of cruelty by the Assad regime flagrantly violate basic principles.
If Assad's actions go unchallenged or are only meekly challenged, more "anything goes" behavior from him and others will surely follow. The world's response to Syria is not just about Syria. It is also about ensuring the freak show of Assad-like leaders around the world recognize it is in their interest to adhere to the fundamental rules of a civilized planet.
Of course, those rules will only be followed if they are enforced. Only America can lead those efforts. They cannot be led by the often inept United Nations, the morally indifferent leadership of China or the many well-meaning but mostly complacent countries in Europe.
They cannot be led by the mix of countries that currently comprise the jumbled and nearly incoherent mess that is the Middle East.
America, with the help of our friends, must act. America's security interests are at stake.
Syria now claims we are in a humiliating "retreat." Russian President Vladimir Putin is mocking us. Iran is helping Syria and assessing our resolve as it moves closer to possessing nuclear weapons.
Bullies and predators exploit weakness, not strength. Iran and Russia are Syria's biggest enablers and they have quite expectedly filled the power vacuum after sensing American indifference to Syria's future.
The U.S. has "talked the talk" about Syria. If all we now offer is more talk, the results will be predictably detrimental to U.S. security interests.
Nearly three years ago, I supported assisting the Syrian rebels before the rebel forces degenerated into a concerning mix of not just Syrian rebels but also foreign fighters and groups with nefarious motives.
That window of opportunity has likely passed. At the least, Congress should now authorize the use of force and President Obama should direct our military to deliver punishing attacks against command and control assets of the Assad regime.
Assad should also be held to account as a war criminal and mass murderer. America and the world should uphold no less of a standard.
This work is the opinion of the columnist and in no way reflects the opinion of ABC News.
Tim Pawlenty is the former governor of Minnesota and GOP presidential candidate.