These are the incredible stories of US troops who've earned the Medal of Honor during the war on terror

• The US's war on terror launched on October 7, 2001 with the invasion of Afghanistan, a campaign known as Operation Enduring Freedom.
• Throughout the 17-year war, 21 service members have received the nation's highest award for combat valor.
• The Medal of Honor is reserved for service members who display extraordinary bravery or selflessness in conflict, often at the expense of their own lives. 

On April 4, 2005, President George W. Bush spoke to a somber crowd gathered to honor Army Sergeant First Class Paul Smith, who had died two years earlier during the Battle of Baghdad. During the ceremony to follow, President Bush presented the Medal of Honor to Smith's parents, inducting their son into a venerated fraction of military service members and veterans.

"Since World War II more than half of those who have been awarded this medal gave their lives in the action that earned it," President Bush said. "Sergeant Paul Smith belongs to this select group."

Smith was the first service member awarded with the nation's highest military honor for his actions during the global war on terror. In the time since, 20 more have been awarded for conspicuous gallantry — an obvious display of bravery in battle that often shows disregard for one's own life.

Here are their incredible stories.

Navy SEAL Senior Chief Petty Officer Britt Slabinski

On March 4, 2002, Navy SEAL Senior Chief Petty Officer Britt Slabinski’s helicopter was shot down over Takur Ghar mountain in Afghanistan. Through deep snow, Slabinski protected his teammates by fighting off insurgent forces, exposing himself to direct enemy fire throughout. At one point, Slabinski carried a wounded teammate to safety while calling in airstrikes for protection. Originally awarded the Navy Cross, in May 2018 President Donald Trump upgraded the award to the Medal of Honor.

Air Force Technical Sergeant John Chapman

Air Force Technical Sergeant John Chapman was posthumously awarded the Medal of Honor over 16 years following his actions during the Battle of Robert’s Ridge on March 4, 2002. After a rocket-launched grenade toppled his team’s helicopter, Chapman led the effort to rescue one of his teammates who was thrown from the aircraft. He fought for over an hour through enemy gunfire, ignoring numerous injuries in the attempt to save Navy SEAL Neil Roberts.

Tech. Sgt. Chapman was originally awarded the Air Force Cross for his actions during the battle, becoming the first Air Combat Controller in history to earn that medal. The Battle of Robert’s Ridge resulted in numerous decorations, including 12 Silver Stars and three Air Force Crosses. President Donald Trump upgraded his award in August 2018, making Chapman the first member of the Air Force to earn the Medal of Honor since the Vietnam War.

“He gave his all for his men”: Sergeant First Class Paul Smith

On April 4, 2003, Sergeant First Class Paul Smith coordinated the defense of over 100 US soldiers who came under attack near Baghdad, Iraq. Surrounded by enemy forces, Smith fought them off with hand grenades, anti-tank weapons, and a truck-mounted machine gun, exposing himself to direct enemy fire. He suffered mortal wounds while saving the lives of wounded soldiers, who were rescued while he provided protective fire.

Sgt. First Class Smith was awarded the first Medal of Honor of the Global War on Terror by then-President George W. Bush on April 4, 2005.