Kerry appeared on five morning talk shows, announcing new evidence – that the neurotoxin sarin had been used in the attack that killed more than 1,400 people – and expressing confidence that Congress would ultimately back the president’s plan for military action.
Behind closed doors on Capitol Hill, the administration presented classified intelligence to any senator or House member who wished to attend. About 80 did, but some from both parties emerged from the briefing convinced that the draft language authorizing military action would need to be tightened.
The rush of activity came a day after President Barack Obama’s surprise decision to seek the authorization of Congress for a strike on the Syrian government.Ahead of an Arab League meeting in Cairo, Kerry sought to mobilize backing for U.S.-led military action at a meeting the group held Sunday night.A statement that was issued by the league asserted that the Syrian government was “fully responsible” for the chemical weapons attack and asked the United Nations and the international community “to take the necessary measures against those who committed this crime.”

To the satisfaction of U.S. officials, the statement did not explicitly mention the U.N. Security Council or assert that military action could be taken only with its approval. But it stopped short of a direct call for Western military action against Syria.

As the meeting got under way, the Saudi foreign minister, Prince Saud al-Faisal, urged the international community to stop the Syrian government’s “aggression” against its people.

Saudi Arabia has been one of the principal supporters of the Syrian opposition, and Kerry consulted by phone on Sunday with Prince Bandar bin Sultan, the head of Saudi Arabia’s national security council.

The Obama administration’s calculation has been that a call for tough action by the Arab diplomats would enable the White House to argue to members of Congress that it had regional backing for military action and would make up, at least politically, for the British decision on Thursday not to join the American-led attack.