Summary : The 2005 National Defense Strategy introduced the now prolific concept of the four challenges -- traditional, irregular, catastrophic, and disruptive. Reference to the challenges is now an essential feature of defense deliberations. Yet in spite of the concept's central place in the defense debates in and out of government, there have been persistent gaps in how the individual challe…
This book explains the causes and recent historical events (during the 1990s and the 21st century) causing the crisis and war in Ukraine. It includes a discussion of how these events put the world at risk of nuclear war. It also touches on some general theory relevant to political science and international relations.--Publisher.