Much has happened in the 16 years since this author penned a monograph entitled Redefining Land Power for the 21st Century. The United States suffered the tragedies of September 11, 2001, the first attack of a wave of large-scale extremist terrorist activities that have scourged the globe from London to Bali to Madrid to Mumbai to Nairobi and beyond. The invasion and subsequent counterinsurgency campaigns in Iraq and the ebbing war in Afghanistan have significantly engaged U.S. military power, especially Landpower, for over a decade. The ongoing volatility of the international security environment continues to generate crises that may embroil U.S. national interests: an increasingly erratic North Korea that may be on the verge of implosion, confrontation with Iran over its nuclear policies, the turbulence of the Arab Spring and its consequences, growing unrest in broad swaths of Africa, and multiple crises in the Middle East, to name but a few.