If you were honestly concerned about the people in Syria, you wouldn't offer them an "umbrella of the United States" after another chapter of war, but you'd support diplomatic efforts between the warring parties, for example in Geneva. Besides, if Israel is concerned about its relations with Syria, I would also try to participate in the conference. If Israel is only concerned about some territorial annexations, it can also stay away.
Palestinian reportedly shot dead by Israeli soldiers after approaching Gaza border fence (Haaretz)
from the article: Why we should support the rebels in Syria