Nah, all of them are not US allies. Most of them, that is, Syrian opposition are pro Turkey. There is a small number of pro US guys in the An Tanaf border crossing. You should read up more on these issues. And who says Syria and Iran doesn't respond at all? They did shoot down an F-16, don't you remember?

They have tried to put up mines in Israeli border several times but failed because they were found out. Iran is slowly building up strength in Syria.