Watching the Syrian crisis in recent weeks has provided answers to two critical and interrelated questions that have hovered over the conflict since it began.
The first is: will the West ever mount a decisive military intervention into the conflict? The answer to that question now seems a pretty clear 'no'.
There may yet be a largely symbolic US strike on the Syrian regime, but the difficulty Washington (and London and Paris) has had mustering political support for even this limited operation underlines the fact that even something short of a Libya-style intervention is a remote prospect.
The one caveat I would put on this is the possibility that the Syrian regime does something so horrible that it jolts the Western moral conscience back into operation. But Damascus has already done very many horrible things and its seems it would take a lot to get a war-weary West out of neutral.
You would think therefore that this renders academic the second question hovering over the conflict since it began: would intervention or the threat of intervention work? There would seem to be no point debating the wisdom of doing something that is not going to happen.
Yet the last few days have provided something of an answer to this question as well. The seeming willingness of the Syrian regime to play along with the Russian idea that it should give up its chemical arsenal in order to forestall military action suggests Damascus does fear such action.
Of course, the whole focus on chemical weapons is a distraction. The overwhelming majority of Syrians killed in the conflict have been killed by conventional weapons. Even if Syrian chemical weapons were now placed under international control it would not have the slightest impact on the blood letting. But even if the regime is not serious about the Russian proposal and is just playing for time, it still suggests that Assad is worried about where even a symbolic strike might ultimately lead.
Moscow seems to share this uncertainty. For the last two years it has both understood Washington's extreme reluctance to intervene and done everything to prevent even the remotest possibility of a change of heart. Hence Moscow's unwillingness to approve even a humanitarian resolution in the UN Security Council out of fear that it might become a back door to another Libya operation.
So there is the irony: Syria and Russia fear what the West plainly does not want to do.
This is not, however, an argument in favour of force. It is one thing to say that Syria and Russia fear the prospect of military action. It is another thing to say that they would capitulate in the face of it. Bashar al-Assad is unlikely throw his arms up in surrender as the first Tomahawk missile enters Syrian airspace. Like Saddam and Qadhafi before him, Assad will need to be literally dug out of the ground before he surrenders. Any serious military intervention in Syria would be as bloody and costly as the West fears.
Nevertheless, there is room for diplomacy between, on the one hand, the regime and its supporters' willingness to take some steps to avoid military action and, on the other hand, its unwillingness to totally capitulate, even in the face of that action.
It means the West needs a real diplomatic strategy that is calibrated to what is possible. The West continues to have a weak hand on Syria, but it could undoubtedly play it better. So while half-hearted threats of force will not make Assad step down, they could be used to grind out concessions he might be more willing (or be pushed by his international allies) to make.
The West should start with chemical weapons. Scepticism about the regime's intentions is justified, but it is an opening that needs to be thoroughly explored. More important would be to work for a ceasefire, as well as any other measures that would help deal with the humanitarian situation. In other words, focus now on dealing with the worst consequences of the conflict.
None of this will be as a satisfying as demanding Assad step down immediately. But for now, having ruled out the intervention that it rightly fears, the West needs to focus on what is possible, rather than what is preferable.