Twenty-five years after 9/11, it is important to step back from today’s cynicism and remember the heroism and national unity in the hours and days after the attacks. On that nearly cloudless morning 25 years ago when terrorists hijacked four airplanes and launched the deadliest attack on America since Pearl Harbor, the country’s initial response was inspired and unifying. Firefighters and police officers climbed the stairs of burning buildings in the face of mortal risk.

Passengers on a doomed jet stormed the cockpit and saved countless lives. Within weeks, the United States, with the world’s support, went to war against the attacks’ plotters and their protectors in Afghanistan. America would claim some major successes.

Al Qaeda, in its original form, was crushed, with almost every leader eventually killed or captured. There has been no terrorist attack against the United States since 2001 that approaches the death toll of that day — 2,977 — largely thanks to work by U.S. forces, intelligence agencies and law enforcement. In the days after Sept. 11, Americans wondered when they might again live without constant anxiety about terrorism.

For years, most of us have done so without even realizing it. Yet this recitation of post-Sept. 11 accomplishments masks a harder truth. The principal legacy of America’s response to that horrible day is not a stronger, more resilient nation.

It is instead two long, bloody wars — one of which, in Iraq, was started on false pretenses — that mostly weakened the United States, at home and abroad. It is an America more isolated from the world. More than 7,000 service members were killed and more than 53,000 wounded in the war on terror.

By one estimate, it cost more than $8 trillion and 900,000 lives.