Across Western nations, fertility rates have collapsed well below the 2.1 replacement level, with many European countries and aligned economies hovering between 1.2-1.8 births per woman. This trend, documented by demographers, stems from rising wealth, women's economic participation, high child-rearing costs, and shifting cultural norms that prioritize individualism over family formation. Visual Capitalist analysis shows Israel as the outlier above replacement, while projections indicate significant population stagnation or decline in Europe, East Asia, and North America, offset only partially by immigration that itself generates societal tensions. IMF analysis highlights how these shifts will drive population drops in countries like Japan, Russia, Italy, and South Korea, raising questions about aging workforces, welfare sustainability, and long-term human progress. In the United States, the non-Hispanic White population share has been declining, a factual demographic transition studied extensively in academic literature. Research published in Group Processes & Intergroup Relations demonstrates that awareness of this 'White population decline' triggers collective existential threat, mediating defensive reactions among segments of the population. Pew-linked studies and sociological reviews confirm that while most Americans view these shifts neutrally, a minority experiences it as a form of cultural erosion or replacement. This anxiety intersects with deeper philosophical nihilism in modern Western societies—decades of secularization, consumerism, and perceived loss of unifying narratives have fostered existential questioning that correlates with suppressed birth rates. What mainstream outlets often frame as neutral 'demographic transition' or economic inevitability appears, through a heterodox lens, as self-sabotage: policy choices around immigration, family incentives, education, and cultural individualism that accelerate native population decline. These patterns provide fertile ground for radicalization. Reviews of far-right extremism, including those from CITAP and parliamentary inquiries, identify 'Great Replacement' narratives—positing deliberate demographic engineering—as a core driver. Such beliefs link directly to online pathways where demographic fear blends with grievances over inequality, globalization, and cultural change, fueling recruitment and, in extreme cases, violence. The 4chan-adjacent discourse of 'Why did the White race destroy itself?' reflects this undercurrent but misses broader corroboration in peer-reviewed work: it is not conspiracy alone but measurable fertility collapse meeting status anxiety that propels radicalization beyond what legacy media typically explores. Connections others miss include how post-1960s cultural shifts toward expressive individualism (echoed in declining religiosity and delayed family formation) create a feedback loop—nihilism lowers births, demographic anxiety rises, and radical movements offer purpose through identitarian revival. Without addressing root drivers like economic precarity for young families or cultural recovery of meaning, these trends suggest deepening polarization.