Right. Of course borders can be closed. Just try to sneak into Saudi Arabia.
Saudi Arabia is the most shameless and hypocritical country in the whole world. First they triggered a civil war in Syria, by arming the Al Nusra Front and the ISIS. And when people started fleeing from Syria, they refused to let anyone inside their country.
Do you really think that it is Saudi Arabia that defends its interests in Syria? Why then is the Russian troops? And who benefits from the fact that the refugees are massively beginning to fill Europe? In connection with the general world discontent there are others who are interested in such processes.