It may already be too late for that. The birth rate among indigenous Europeans is too low and the age too high to support a demographic comeback. Further, the "open borders" crowd is a long way from being deposed. Finally, the "non-violent" ethic and individual disarmament (except the Swiss) engrained since World War II shows no sign of abatement. If there was a new "El Cid," when he tried to raise an army, nobody would show.