The purpose of this thesis is to inquire into the hard decisions that democracies are making in the 21st century in the context of working to spreading democracy and maintaining peace through foreign policy. Ever since the American-led invasions of Afghanistan and Iraq after the 9/11 terror attacks, democratic peace theorists have been pushed further to the sidelines as their theory has been put to the test and struggled to stand up to the challenges of political realities in contemporary world politics. The idea that the diffusion of democracy would help build a Kantian world peace would seem to have taken a severe blow with the rise of populist candidates and policies in the West in recent years. The democratic peace theory (DPT) is in crucial respects about the mechanisms to indirectly control other countries' economies and politics through forcibly installing democratic regimes. Though done in the name of safety and security for western nations, this foreign policy looks an awful lot like an attempt at biopolitical engineering. Has DPT morphed into a form of biopolitics? The goal of this thesis is to delve into this question and to learn what the implications are if this is the case, and what it means for the West, democracies, terrorism, and societies. For if democracies are less and less able to justify their role in driving the proper conditions for peace, we must scrutinize the role they play in international affairs in a much broader political perspective.