Everyone in the region knows that the transfer of chemical weapons to Hezbollah or the acquisition of the Fateh-110 missile, with the accuracy and range to hit the heart of Tel Aviv, is a red line. Hence the punishing Israeli airstrikes around Damascus on advanced weaponry making its way to Hezbollah. …

Today our only hope seems to be supporting and arming Salim Idriss, the one rebel commander who speaks in moderate, tolerant tones. But he could easily turn, or could be overwhelmed by the jihadists. As they say in the Middle East, you don’t buy allies here. It’s strictly a rental.

Israel’s successful strikes around Damascus show that a Western no-fly zone would not require a massive Libyan-style campaign to take out all Syrian air defenses. Syrian helicopters and planes could be grounded more simply with attacks on runways, depots and idle aircraft alone, carried out, if not by fighters, by cruise missiles and other standoff weaponry.

But even that may be too much for a president who has assured his country that the tide of war is receding. At this late date, supporting proxies may be the only reasonable option left. It’s perversely self-vindicating. Wait long enough, and all other options disappear. As do red lines.