Lessons from Afghanistan?

What started out as a justifiable intervention in Afghanistan has now become America's longest war (going on 12 years).  It has also become the most unpopular.  In Afghanistan, there was never even a humpty-dumpty to put back together again.  All the idealistic talk about nurturing democracy there was a delusion. Although we are out of Iraq, are the Iraqi people better off for our involvement?  Is democracy flourishing in our long-term ally Egypt?    The bad taste created by the Afghani and other debacles has made the public skeptical about intervention in Syria?  One suspects that give the horrendous brutality, threats of Iranian retaliation if the U.S. strikes, growing regional involvement (e.g. Lebanon's Hezbollah), transformation into a Sunni-Shiite war, etc., etc., etc,, that Syria can never be put back together again, by anyone, no matter what.  Recently increasing sectarian violence in Iraq, also sends disturbing messages.  In addition, recent news suggests more brutality by the Syrian rebels than previously revealed.  The rebels and their backers have tried to keep a lid on this news, but it is more than just Assad's propaganda. Syria is becoming a basket case that cannot be fixed by outside intervention.  Obama has thus far failed to get additional support at the G-20 meetings. Our closest ally, Britain has already opted out. It is far too late for missile strikes or even no-fly zones.  Congress and Obama should just suck it up.  Obama should admit he has blown it, and the politicians need to listen to the American public--except for humanitarian aid, no direct American involvement in Syria.