First, there must be a very short fuse for Bashar Assad to turn over the weapons. And when he does, there must be full and strong verification, including the immediate admittance into Syria of internationally respected experts on chemical weaponry.

If Russia is sincere and Syria plans to comply, the experts can arrive within hours or days, and the turnover can be completed within a week to 10 days. This position — expeditious action and full verification — should be non-negotiable, and it has been emphasized by President Obama, Secretary of State John KerryJohn Forbes KerryJohn Kerry’s memoir title revealed GOP senator: Democratic opposition to Pompeo 'driven 100 percent by politics' North Korea is moved by Pompeo diplomacy, but Dems dig in deeper MORE, former Secretary of State Hillary ClintonHillary Diane Rodham ClintonFormer presidents, first ladies come together to honor Barbara Bush Romney: Parts of Comey book read 'too much like a novel’ Collins: Comey should have waited to release his memoir MORE and Sen. John McCainJohn Sidney McCainRomney forced into GOP primary for Utah Senate nomination Trump considering pardon for boxing legend after call from Sylvester Stallone GOP poised to advance rules change to speed up Trump nominees MORE (R-Ariz.), among others. It is not necessary to trust anyone; it is necessary to verify everything. 

Second, let's be clear about what is happening. Russian President Vladimir Putin suggested this plan because he came to believe in the credible threat that the U.S. would spearhead a targeted and focused military strike against the Syrian capacity to use chemical weapons again. It is immaterial whether Putin believed Congress would ultimately pass the resolution or that Obama would take military action regardless of congressional votes. If Putin had concluded that Congress would refuse to act and Obama would then decline to act, he would never have made this proposal.

Had the opponents of all military options prevailed, Putin and Syria would have gladly accepted their triumphant victory over our lack of will. This is why I have so strongly praised both Republican and Democratic leaders who joined in the call to act. House Speaker John BoehnerJohn Andrew BoehnerA warning to Ryan’s successor: The Speakership is no cakewalk With Ryan out, let’s blow up the process for selecting the next Speaker Race for Republican Speaker rare chance to unify party for election MORE (R-Ohio), House Democratic leader Nancy Pelosi (Calif.), House Majority Leader Eric CantorEric Ivan CantorRace for Republican Speaker rare chance to unify party for election Scalise allies upset over Ryan blindside on McCarthy endorsement 2018 will test the power of political nobodies MORE (R-Va.), Senate Majority Leader Harry ReidHarry Mason ReidGOP poised to advance rules change to speed up Trump nominees Dems walk tightrope on Pompeo nomination The Memo: Teens rankle the right with gun activism MORE (D-Nev.) and McCain performed a huge service to American security, America's deterrent capability and the cause of nonproliferation of chemical weapons by their steadfast position.

Also, this is why I have praised the forcefulness and resolve of Kerry both in his strong approach to Syria and his Herculean efforts to bring Israelis and Palestinians together for a regional peace based on a two-state solution. 

And special commendations have been earned by President François Hollande of France, whose clarity and courage on the Syria matter are the acts of a world leader making a great contribution and having a crucial impact.

Let's be clear about this as well: The Russian plan may be a clever fraud to buy time for new mass murders by Syrian tyrants. I do not offer an opinion; the facts in coming days will speak for themselves. This is not a time for celebration; it is a time for clarity and resolve.

I would again urge members of the House and Senate to support giving the president the authority to employ targeted military force if diplomacy fails. This is the best way to help diplomacy succeed and to avoid actually having to employ military force, but we would make it clear to one and all that America is prepared to act with force if necessary.

It is not yet clear whether the Russian plan is the end of the beginning or the beginning of the end of chemical weapons in Syria, but one way or the other, mass murder by chemical weapons, a crime against humanity, must not be tolerated.