The US Secretary of State, John Kerry, did far more than just set out the intelligence against Syria. But he did do that.
Although there is now more detail than we had before about the attack, there is no damning proof.
Indeed, perhaps for understandable reasons, there is no proof at all - only assertions that we must take on trust. As Mr Kerry himself suggested, after Iraq trust is in short supply.
He did far more than set out a moral case for military action. What he did was make it impossible for President Barack Obama to back away from it. He said if the US didn't act, history would judge them harshly.
If they turned a blind eye, it would embolden dictators in Iran and North Korea and leave the US without credibility in the world.
Mr Obama has made similar points himself. It is not the first time Kerry has made the case. But these were the strongest words yet.
When Mr Obama spoke he sounded pretty downbeat by comparison, although he too pointed firmly towards some form of action.
But he was keen to stress that any action would be limited, unlike Afghanistan or Iraq, and would not involve boots on the ground. There are increasing mutterings from Congress, asking him how certain he is of that.
The president said he had made no decision. It is not clear when he will.
Mr Kerry suggested there would be a "conversation" with the American people before action.
There's not much time to talk and, in the next few days, many Americans will be hanging metaphorical "gone fishin'" signs on their front doors. This is Labor Day weekend - a big holiday in the States - and perhaps not the ideal time for a conversation about war.
Perhaps the president hopes a lot of people aren't paying much attention. But if action doesn't come in the next few days, it may have to wait for next weekend or beyond. The president goes to Sweden on Tuesday, then on to the G20 in Russia.
There is no iron law saying the president can't order military action while abroad. But it would be odd.
To do it while he's in Russia would be downright weird and highly provocative. He could cancel the trip but the White House says his plans are still in place.
After his Secretary of State has ramped up the rhetoric about the historic, momentous importance of sending a signal, leaving it a week might be too long.
So, many people think there will be action on the weekend or Monday.
But frankly it's a guess. With this decision even the timing is awkward for the president.