To Breivik, demographic change has revitalized Marx’s dream of a predictive science of history. Analysis of fertility rates and immigration allows predictions of the relative size of these cultural communities within Europe over the next several generations. Comparative analysis of conditions within countries with different-sized Muslim populations—e.g., Finland vs. Saudi Arabia—shows the stages European countries are likely to endure.
In particular, the chaotic histories of Lebanon and Kosovo, in which Muslims became dominant through immigration and higher fertility, show what Europe can expect in the middle of the 21st century. Lebanon was, by Middle Eastern standards, prosperous and sophisticated under a Christian majority, but the rise of a Muslim majority led to the awful civil war of 1975-1990.
In online discussions, Breivik advanced some of these ideas. But he maintained a passive public façade of quasi-Marxian historical determinism about the inevitability of these changes so that he wouldn’t be suspected of plotting violence. This served to hide his secret Leninist side, his determination to go down in history as the prophet and first mover of the armed resistance.
Did the Marxist-Leninist heresy he invented motivate his atrocities? Perhaps, but I suspect that he is less a true believer in his own rhetoric than a devious marketer looking to promote himself, even (or especially) if he had to do it in the worst way possible.