Bashar al-Assad’s most recent, unconscionable transgression against his own people has rekindled a years-old debate. America, and the world, must decide again just how to deal with Syria.

It’s safe to say that Washington is unified in decrying Assad and demanding his replacement. However, there are sharp disagreements, especially within the Republican party, about how to achieve that.

The Wall Street Journal reported last Thursday that U.S. Ambassador to the United Nations Nikki Haley told the U.N. Security Council that the U.S. would be “compelled to take our own actions” if the international community doesn’t satisfactorily react to Assad’s attack, connoting military intervention of some sort.

Senator John McCain, historically one of the more hawkish Republican senators, also supports military intervention in Syria. As his statement on the attack indicates, he believes Assad’s crossing the metaphorical line once again merits military action. He argued that “[Assad] must pay a punitive cost for this horrific attack.” He continues to argue that though “there is plenty that Democrats and Republicans in Washington disagree on,” they must get together to destroy Assad’s air force.

McCain ought to be as worried about getting Republicans on board with that proposal as he is the Democrats.

Senator Rand Paul, as a member of the Senate Foreign Relations committee, has perhaps the most influential voice for non-interventionists on the Right.  Though he has agreed with the President on other issues, he decried the decision to bomb Assad.  Paul kept his official statement terse at three sentences. He reminded us that “prior interventions in this region have done nothing to make us safer, and Syria will be no different.”

Diplomacy in the Middle East has never been easy, and Syria will become tougher before it gets easier.  Following Republicans’ failure to pass a healthcare bill, Syria appears to be the next big issue to test Republican unity.