Four decades ago, Secretary of State Dean Acheson titled his memoir on the construction of the post-World War II order, "Present at the Creation." Looking out at the state of that order today, it is fair to ask if we are now present at the unraveling. For 7 decades, Republican and Democratic leaders alike have committed America's indispensable leadership and strength to defending a liberal world order, one that cherishes the rule of law, maintains free markets and free trade, provides peaceful means for the settlement of disputes, and relegates wars of aggression to their rightful place in the bloody past. America has defended this order because it is as essential to our identity and purpose as it is to our safety and prosperity. But the liberal world order is imperiled like never before. A revisionist Russia has invaded and annexed the territory of a sovereign European state, the first time that has occurred since the days of Hitler and Stalin. A rising China is forcefully asserting itself in historical and territorial disputes, and alarming its neighbors, all the while investing billions of dollars in military capabilities that appear designed to displace and erode United States power in the Asia-Pacific. A theocratic Iran is seeking a nuclear weapon, which could unleash a nuclear arms race in the Middle East and collapse the global nonproliferation regime. A vicious and violent strain of radical Islamist ideology continues to metastasize across the Middle East and North Africa. In its latest and potentially most virulent form, the Islamic State, this evil has the manpower and resources to dissolve international borders, occupy wide swaths of sovereign territory, destabilize one of our most strategically important parts of the world, and possibly threaten our Homeland.