The Navy SEALs:
Unfazed and Undeterred

Born in World War II

Beginning with the standing up of the Amphibious Training Base at Little Creek, Norfolk, Virginia, followed by the standing up several units, including the Amphibious Scouts and Raiders, the Naval Combat Demolition Units (NCDUs), and the Underwater Demolition Teams (UDTs) (all formed during World War II)—these units crafted the training and doctrinal precursors to the modern-day units known as the Navy SEALs. These early units trained for and participated in actions in both the European and Pacific theaters, and were instrumental in the D-Day landings in Normandy, France (by way of NCDUs).

The WWII units that eventually led to the Navy SEALs include:

• Amphibious Scouts and Raiders

• Special Mission Naval Demolition Unit [Operation TORCH]

• Operational Naval Demolition Unit & Naval Demolition Unit No. 1 [Operation HUSKY]

• Naval Combat Demolition Units (NCDUs) [D-Day (37 KIA, 71 WIA) & Operation DRAGOON]

• Special Services Unit ONE (SSU-1)

• Underwater Demolition Teams (UDTs)

• Office of Strategic Services Maritime Unit

UDTs in the Korean War—the SEAL Teams' Direct Forebears

UDT-1, UDT-2, UDT-3, and UDT-4 are the direct forebears of the modern-day SEAL Teams. During the Korean War UDTs conducted numerous raids and direct actions, including at Yeosu and during Operation CHROMITE—followed by mine-clearing roles at Wonsan Harbor, a large port destruction at Hungnam Harbor, and in Operation FISHNET/SEANET.

UDTs in the Space Race

Throughout the Space Race, UDT swimmers played a key role in both training astronauts how to safely exit their spacecraft (upon returning in the ocean), followed by serving the Mercury, Gemini, and Apollo space programs by recovering the returning astronauts—including for Apollo 11 (the human first lunar landing).

Forging the SEAL Teams

Spurred by the changing dynamics that exceeded the mission set and responsibilities of the UDTs, and recognizing the need to develop special operations forces with a refined focus on unconventional and guerrilla warfare, various staff officers (including the Chief of Naval Operations Admiral Arleigh A. Burke) worked through and submitted proposals for meeting these new requirements. Driven by a multitude of threats across the hemispheres that required a more delicate and surgical approach (often in order to avoid a full-scale war), two SEAL Teams were stood up in January of 1962, following President John F. Kennedy’s direction to the Secretary of Defense to stand up and enhance various kinds of special operations and special forces units—with an emphasis on coordinating with the locals in theater.

Vietnam and Beyond: Modern-Day SEALs

Since the Vietnam War, SEAL Teams have taken on various mission sets in combat operations across the globe. From the training of Republic of Vietnam forces (prior to the United States’ official entry into the Vietnam War), to the squads and platoons of SEAL Team ONE and SEAL Team TWO (along with their Mobile Support Teams), the SEALs substantially disrupted Viet Cong operations in the RVN.

In 1972, despite only serving as advisors (as all active-combat SEAL platoons had already left the RVN at the end of 1971), two SEALs (LT Thomas Rolland Norris and LT Michael Edwin Thornton) earned the Medal of Honor, while both serving as advisors.

Beyond Operation URGENT FURY in Grenada and Operation JUST CAUSE in Panama, Navy SEAL Teams have become an integral component of U.S. Special Operations Forces, and have contributed valiantly and definitively to numerous high-stakes missions—in the Global War on Terrorism and beyond.

While operations such as the successful elimination of Osama bin Laden (who founded al Qaeda and directed numerous attacks against U.S. interests, and ultimately, the World Trade Center, Pentagon, and Flight 93 attacks on September 11, 2001) rightly color the recent history of the modern-day SEAL Teams, the operational accomplishments and status as an indomitable deterrent to our nation’s adversaries transcend the well-documented narratives of their publicly available exploits. What the Navy SEALs have and continue to contribute to the collective security of the nation and its interests will likely never fully come to light due to the clandestine, inherent nature of their mission sets and often unseen presence/roles.

For more on how the Navy SEALs became the expected unit for the most unexpected of missions:

• "Joint-Service Beach Obstacle Demolition in World War II"—James Douglas O'Dell

• "SEALs: 50 Years and Counting" (2012)—Naval History—Dick Couch

• "Fearless Since 1962: How the SEALs Became the Navy's Most Elite Force"—Katie Lange (Department of War, 20 Jan 2026)