“It sure is hell to be president.” Harry Truman spoke from experience.

One his worst days was April 14, 1950.  That’s when the National Security Council delivered a highly classified, 58-page report calculating the forces needed to fight the Cold War. Truman blanched. The numbers didn’t fit with his intent to trim defense budgets. He shelved the plan.

Two months later, everything changed. North Korea invaded the south. Truman became an instant convert to peace through strength. The administration launched a nationwide campaign stressing the importance of adequate defense spending.

Recently, the House Armed Services Committee sent President Obama a report outlining cuts the military would have to make under the “sequestration” formula in this year’s Budget Control Act.

Unless Congress and the president agree to an alternative long-term plan to reduce the deficit (supposedly coming from the so-called “Super Committee”), the act provides for automatic reductions in “discretionary” spending.

That means huge cuts to the Pentagon budget. In 2013 alone, sequestration would slash defense spending up to 18%. Over 10 years, the military would take a $1 trillion hit.

The HASC report translates those near-abstract numbers into what they would mean in terms of reductions in military force. The results are stunning. Every service would lose substantial capabilities.

America’s Army would lose a quarter of its active duty troops, leaving the service smaller than it was on 9/11. The scramble to assemble enough forces for Iraq and Afghanistan clearly demonstrated that the pre-September 11 Army was too small to deal with even moderate-sized contingencies.

The Navy could lose two carrier battle groups. That can’t make sense. The Navy carrier force is already too small to cover the world. When Obama committed U.S. forces to Libya, he found there was no carrier available.

The Air Force would have about of one third of the fighter planes it had in the 1990s, and even after that kind of force-gutting, there would be scant funds to buy next generation aircraft like the F-35 fighter.

Stuck with such a shrunken, mostly same-old, same-old fleet, the U.S. can never plan on having air supremacy in future conflicts—especially given the pace that potential adversaries such as China are pursuing next generation fighters and advanced air defenses of their own.

The Marine Corps makes out worst of all. Truman didn’t care much for the Marines. He once said, “the Marine Corps is the Navy’s police force and as long as I am president that is what it will remain.”

Any president who would let “sequestration” happen can’t think much more of the corps. Sequestration cuts would leave the corps short so many amphibious ships that its ability to mount any significant operation would be questionable, at best.

The Pentagon has been passing around the HASC report like Halloween candy, but the White House has yet to send a clear signal to Congress. Obama has already laid out $450 billion in defense cuts—reductions that are already eroding force capabilities and readiness. Additional cuts would simply leave the U.S. even that much less of a military power than we were when Obama came into office.

Now is the time for the president to flat out tell the Super Committee and the Congress that more defense cuts are simply unacceptable.

Should the Pentagon be forced to implement further budget reductions, any occupant of the White House confronted with the need to use the military to protect america’s interests will be in for a rude awakening.

Then they will feel the truth of Truman’s words ““It sure is hell to be president.”

James Jay Carafano is a senior research fellow for national security at The Heritage Foundation.