The need for an immediate United States response in Syria to discourage the further use of chemical weapons does not change the fundamental dilemma of US policy, which is that - for very good reasons - the US does not want either side to win this war.
Victory for either side would mean dreadful massacres and ethnic cleansing, as well as an increased threat of international terrorism.
What the administration now needs to do is to start thinking seriously about the real contours of a Syrian peace settlement, and to turn the Syrian crisis into an opportunity to rethink its overall strategy in the Middle East.
In the long run, if Syria is not to disintegrate as a country, there will have to be a peace settlement that guarantees the sharing of power among Syria's different ethno-religious groups. The participation of Russia, Iran and Iraq in such a settlement will obviously be essential.
Washington therefore needs to separate its immediate moral rhetoric in justifying an attack from the language it uses towards Moscow, Teheran and Beijing concerning Syria.
It would be helpful in this regard for US officials to understand that Russia's fears concerning the consequences of a rebel victory are neither wicked nor irrational, but are shared by many analysts in the Central Intelligence Agency, the State Department and the Israeli government.
The importance of Russia to the conflict in Syria lies both in its links to the Baath regime and its good relations with Iran.
A deeply negative consequence of the intensifying Syrian crisis has been to undermine the possibility of a new dialogue with Iran that was opened by the victory of the moderate President Hassan Rouhani in June elections.
One of the grave problems of the Syrian civil war for US policy has been that it has risked entangling the US even more deeply in an anti-Iranian (and, historically at least, anti-Russian) alliance with the Sunni autocracies of the Persian Gulf that back the Syrian rebels.
This alliance sits badly with the US' own secular and democratic values, and with its hopes for progress in the Muslim world. The sponsorship of Sunni Islamist extremism by some of these states poses a threat to American security.
Using Moscow to develop new relations with Iran is therefore necessary, not only for a resolution of the Iranian nuclear issue and (eventually) of the Syrian conflict, but also in the long run for the restoration of basic stability in the Middle East.
And it should be noted that while Russia has preserved good relations with Iran, it has also on occasion been prepared to be tough with the country. The intensified United Nations sanctions eventually agreed to by Russia and China had a severe effect on the Iranian economy and seem to have contributed significantly to Mr Rouhani's victory in Iran's elections.
Of course, a Syrian peace settlement will be terribly difficult to achieve, and will probably not be achievable until both sides have fought themselves into a state of exhaustion.
Nonetheless, the basic contours of any long-term settlement are already clear, as is the need for Iranian and Russian participation.
Dr Anatol Lieven is a professor in the war-studies department of King's College London and a senior fellow of the New America Foundation in Washington.
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