You see, I was under the impression that stability in the Middle East resides in preserving the regimes. This is how the US referred to Gulf regimes and the Iranian regime of the Shah, that they are stabilizing forces and that opposition to them is destabilizing them. And then I encountered this sentence in the New York Times: "Iran remains a destabilizing force in Syria, and its neighbors view its efforts to prop up President Bashar al-Assad". That adds another layer to the meaning. So it is stabilizing to protect and preserve Arab regimes with the exception of those regimes who defy the US will. In those rare cases, it is stabilizing to overthrow those regimes.