From my little reading of history of Spain I recall a theme. Muslims took over areas of Spain. But the people were Christian.  [So in those areas the rulers were Muslim, but the population were Christian.] That was the setting for the next stage. "Soft jihad" you might call it. That was like this. Muslim adults would be great people. But their teenage boys would venture into the towns of the Christian and do acts of violence. More or less events of jihad. So two opposite streams tended to soften the population to eventually accept Islam. That is kind of how I recall the events in history but I have not read upon this in detail. [I think it was this process which ignited the Martyrs of Cordoba where some people would seek to be martyrs by going up to some Muslim and opening insulting them knowing the penalty.] So it seems like jihad sometimes does work.

[ It is a political problem. And I think that the Constitution of the USA has solved the political problem on how to create a just society. But it seems to work mainly with a Protestant society. So how could one deal with the issue of a different kind of population in a society that is "post Christian"{lukewarm of not at all}?  But looking at Hegel I did not see much helpful, because his forte was philosophy, not politics. Socialism has the basic problem that the very first Plymouth colony discovered when the Pilgrims went to settle in America. Why should the industrious work to feed the lazy?  So when the founding fathers of the USA were dealing with this problem they decided that the Constitution and their system could only work with a kind of people that had an essential set of values. [Basically Christian values as in family, belief in God, in kindness.]