History says maybe not. The Persian Empire, the first great addition to Mohammed's spawn was probably not conquered but rather the rulers made a deal with he Arabs to ally with them against The Byzantines. The Conversion of the Persians probably, as archaeology and the coinage suggests, took a century or more. The rulers converted as part of their deal and retained their status in the new super-horde. The ruling classes of Europe
and America seem to be trying to do that now. They may pull it off. If Trump and the Euros can't get to expelling the Moslems we are all lost to the Islamic flood. Slapping down Mad Mo jihadists and terror cells is not good enough because the are all potential jihadists and as many as are needed will be called and will answer the call. The very best intelligence id not good enough do long as the Mohammedans are allowed to remain in the country. Several European countries now have troops in the streets more or less permanently but they still refuse to name the enemy. It is war now and we cannot name or really see the enemy. We permit them to remain in our midst thinking soldiers can control those they are not permitted to identify.
Even Donald Trump pussyfoots on the identity of the enemy calling them Radical Islamists. There are no radical Islamists if that term is to mean what we think of as Fundamentalists when ascribed to Christians. All Moslems believe the same things. Their bloody arguments center around who has the right to rule, not on the nature of the rule. Every Moslem is a "fundamentalist" or he is no Moslem, at worst he is an apostate, at best an atheist- both of which incur a death penalty by reason of less than pure belief.
Mohammed and Charlemagne: Epilogue
The book