In case of mive invasion,would our european allies help us?

This question is just a what if...in case the U S A where facing invasion from any nation...would are allies support us whit men/gun power/supplies,to help us send them packing and win the war?And if they(and probably won t),after we won(if),would we crush our betraying allies?If i was allies to us(U S A) ... i would probably evan help the invaders to at least overthrow this sick government...I mean...we have a rich history on picking the week ones...Do you really think our allies would rush to aid us in case of an invasion?