Book excerpt: The military posture and capability of the United States of America are, today, dominant. Simply put, there is no external adversary in the world that can successfully challenge the extraordinary power of the American military in either regional conflict or in "conventional" war as we know it once the United States makes the commitment to take whatever action may be needed. To be sure, the first phase of a crisis may be the most difficult-if an aggressor has attacked and U.S. forces are not in place. However, it will still be years, if not decades, before potential adversaries will be able to deploy systems with a full panoply of capabilities that are equivalent to or better than the aggregate strength of the ships, aircraft, armored vehicles, and weapons systems in our inventory. Even if an adversary could deploy similar systems, then matching and overcoming the superb training and preparation of American service personnel would still be a daunting task.