"Doesn't seem very relevant to the present, though, as ISIS is not making its territorial gains through air power." - Richard Bridge

Sorry Richard I thought your concern was for those about to be butchered not exchange of real estate.

Relevance as I seem to have to spell out for you in the light of the question you originally asked is as follows:

In 1991 Saddam Hussein threatened and attempted to kill thousands of Iraqi Kurds in retribution in the immediate aftermath of his defeat Desert Storm - The UK from NATO bases inside Turkey mounted a land and air operation to prevent that.

Today ISIS forces threaten to kill 40,000 of Iraq's Kurdish Yezidi religious minority - You asked who could come to their aid - at least that is what I thought you were asking? Answer of course would be the Iraqi Armed Forces provided that waste of space Nouri Al-Maliki can get his act together.