"Obama and Cameron deserve to be defeated."
Then the world has to come up with an alternative.
The Arab Spring offered a challenge to many of the despots that have ruled the Middle Eastern countries and caused much of the trouble there.
The West has gone along with many of these despots because it was in their interests to do so, oil being the main attraction; it was largely this that forced a degree of support for the Arab Spring protests, a hope to maintain their oil supplies whoever took over.
Whatever oil Syria has will run dry within the next fourteen years and Syria will become an oil dependent country, so she is of no real interest as a trading partner to the West.
Past tolerance of Syrian human rights abuses has led to the present situation in Syria; up to now the world has given the Assad family a free hand and allowed him to use whatever methods he chose to subdue his people, he has even been sold arms to maintain his grip on the country, before and after the revolts began.
Western inaction has led to the protests in Syria turning into a civil war, largely using the Russian/Chinese vetoes as an excuse to do nothing; David Steele put it in a nutshell at the time the people of Homs were being slaughtered, "it is not in Britain's interest to get involved".
If Assad gets away with what he is doing, the Middle East will remain    a series of feudalistic states run by despots, and whatever progress has been made through the revolts stand a fair chance of being lost.
The West cannot stand by and let that happen; morally we are obligated to make up for our various governments' past mercenary policy in supporting the human-rights monsters and allowing them to indulge in their monstrous behavior, even by supplying them with the wherewithal to do so.
Politically it is in our interest to bring Assad down and see that his behaviour is not repeated elsewhere.   
To do nothing is only a continuation of the West's policy of turning a blind eye and selling despots weapons to establish a degree of stability within their realms - 'let the Arms Trade Fairs continue'.
It is interesting to remember that in January 1980, around the time fifty-two Americans had been held hostage in Iran for 444 days, Time Magazine named Ayatollah Khomeini 'Man of the Year' - Western predatory cynicism at its best.
Jim Carroll