International relations since the end of the Cold War have been relatively uneasy, yet we should not discount the fact that the intensity of conflicts has decreased compared to the situation in both the first and second halves of the 20th century. This book explores international security relations as the pandemic subsides and the war in Ukraine escalates, offering a good description of the main actors and the background of current threats. It lays the theoretical foundations for security economics, analyses U.S. foreign policy, introduces China as a new superpower and signals Russia as a great power in decline. It concludes by pointing out the pitfalls of exporting democracy and presenting the paradox of progress. The author asserts that we should not be alarmed that international relations are shifting. Following the Cold War, the U.S. achieved clear strategic and economic superiority, however, China, Russia, India and other great powers remain strong players that must be taken seriously. The book shows that asymmetric warfare often ends with the weaker side winning and the stronger one losing and being discredited. Different examples of this outcome include the American War in Vietnam (1965-73), the Soviet Union's defeat in Afghanistan (1979-1990), and the U.S. getting mired in the wars of Afghanistan and Iraq. The war in Ukraine is a demonstration of the illusion of an imperial power that believes it can impose its will on other nations, even against their will. The book will be a useful resource for academics, students and researchers, as well as policymakers and professionals interested in issues related to international security and defense.