To succeed in the post-1918 world, the world Woodrow Wilson dreamed up where “small nations” have rights even if they can’t defend them, you need to use slower, less obviously military methods, like birthrate and immigration.
The classic example of this kind of slow conquest is Kosovo. The Serbs could always defeat the Albanians on the battlefield, even when outnumbered, but the Albanians had a huge advantage in the most important military production of all—babies. According to the BBC, the birthrate of Kosovo Albanians 50 years ago was an amazing 8.5 children per woman.
The Serb/Albanian conflict offers damn near perfect lab conditions to prove my case that birth rate trumps military prowess these days, because the Serbs always beat the Albanians in battle, yet they’ve lost their homeland, Kosovo. Here again, we can blame Woodrow Wilson and his talk about “rights.” In places where tribes hate each other, a tribe that outbreeds its rival will become the majority, even if it can’t fight. So, after generations of skulking at home making babies, letting the Serbs do the fighting, the Albanians finally became the majority in Kosovo and therefore the official “good guys,” being oppressed by the official “bad guys,” the Serbs. At least that’s the way the naïve American Wilsonian types like Clinton saw it. So when the Serbs fought back against an Albanian rebellion in Kosovo, and dared to beat the Albanians, Clinton decided to bomb the Serbs into letting go of Kosovo, the ancient heartland of a Christian nation that had spent its blood holding off the Turks for hundreds of years.
Now, what helped the Albanians in this endeavor were two things. First, after 1945, Serbs had little or no authority in Kosovo (or Serbia, for that matter), so they could do little to stop this. Secondly, Tito's regime plowed massive resources - plundered from all over Yugoslavia - into the Albanian-dominated province, building schools, hospitals, factories, apartment blocks and other benefits of civilization. One notable thing is that the Albanian birth rate did not drop with urbanization - quite the contrary, it rose thanks to better medical care.
This is precisely what KFOR commander de Marhnac spoke of last November: Albanians not only outnumber the Serbs, they also out-breed them by orders of magnitude. And if the Serbs dare procreate, there's ways of fixing that.
Kosovo is not just a case study of successful (for the time being, anyway) demographic warfare. It is also a case study in how not to oppose it. A military response, even a successful one, can be used as a pretext for an actual invasion (i.e. the 1999 NATO bombing/occupation). It is inhumane by definition, and opens one up to charges of "genocide," whether deservedly or not. The only way to resist this sort of takeover is prevention. This means not just tighter immigration controls - though there is good sense in not letting just about anyone in, let alone people who wish you ill - but tackling the core vulnerability that demographic warfare has been designed to exploit: the welfare state.
Without a way to saddle someone else - preferably the host society - with the expense of delivering, feeding, educating and employing all those "weaponized" babies, any project of demographic conquest is effectively stillborn.