Fifteen years ago this Sunday, nearly 3,000 Americans were killed in the deadliest attack on the U.S. homeland in our history. A decade and a half later, we remain at war with Islamic terrorists. Winning this war will require an effort of greater scale and commitment than anything we have seen since World War II, calling on every element of our national power.

Defeating our enemies has been made significantly more difficult by the policies of Barack Obama. No American president has done more to weaken the U.S., hobble our defenses or aid our adversaries.

President Obama has been more dedicated to reducing America’s power than to defeating our enemies. He has enhanced the abilities, reach and finances of our adversaries, including the world’s leading state sponsor of terror, at the expense of our allies and our own national security. He has overseen a decline of our own military capabilities as our adversaries’ strength has grown.

Our Air Force today is the oldest and smallest it has ever been. In January 2015, then-Army Chief of Staff Gen. Ray Odierno testified that the Army was as unready as it had been at any other time in its history. Chief of Naval Operations Adm. Jonathan W. Greenert testified similarly that, “Navy readiness is at its lowest point in many years.”

Nearly half of the Marine Corps’ non-deployed units—the ones that respond to unforeseen contingencies—are suffering shortfalls, according to the commandant of the Corps, Gen. Joseph F. Dunford Jr. For the first time in decades, American supremacy in key areas can no longer be assured.