During the annual meeting of the Association of the United States Army, Army Chief of Staff General Mark A. Milley took the time to discuss the greatest myths perpetuated on Capitol Hill.

Lawmakers make policy choices based on delusions of how the military operates and what the troops on the ground are capable of accomplishing. Most Congressmen who perpetuate these myths in order to further their own agendas, Milley said, have “never actually experienced the blood and the sweat and the tears of war.”

One of these myths is that wars are short. Citing examples such as the American Revolution, World War I and the Vietnam War, Milley noted that no leaders ever thought the conflict would last so long or have so many consequences across the world.

“Wars are funny things. They have a logic all of their own. And they rarely conform to preplanned timelines,” the general said. “They’re rarely short.”

Modern weaponry also isn’t enough to ensure a short conflict. Using the example of Iwo Jima, which was bombed for weeks during World War II before Americans stormed the shores and met violent resistant, Milley argued that relying on devastating weapons to win wars is a “fantasy.”

“After the shock and awe comes the march and fight,” Milley stated.

Milley stressed that the common belief that the Army’s ranks were endless was also harmful. It takes upwards of 15 years for the military to develop a strong battalion commander. Leaders don’t spring from nothing, and sacrificing too many fresh soldiers on the front lines can cause a leadership vacuum in the future.

The general’s effort to debunk these military myths is important because President Obama and Congress are currently hashing out a new defense spending bill. The White House is also making big foreign policy decisions about fighting ISIS and al-Qaeda that will eventually trickle down to the troops.