I don't think you and I agree very often on politics, but you are on the money here.It's a complex issue. But we have been screaming democracy and liberty for years and when a popular revolution began in Syria and he gunned down crowds of protestors we did nothing. When Gaddafi did it we all went in and consolidated our interests.
Syria was not complicated. There was very little ISIS or AQ initially and if a no fly zone had been established early on, huge swathes of the population would be alive and many more not displaced. Now the people are dead and their relatives are angry and being radicalised as nobody else other than Jihadi nutters seem to care.
Going forward these is no good solution. Iran, Hezbollah and a Russia have made a serious pact. They defecto control Iraq. Are pushing Shia sects in Yemen and a messy battle between Arabs and Shia is happening. Syria is full of hardcore Jihadis who are for the most part not ISIS but are still pretty nuts. Who takes over if he goes?
Ultimately human life has come second to a political game of chess and it's awful.