The transatlantic alliance may be undergoing a long-term shift. Building independent defense capabilities would be extremely costly for Europe. New regional alliance or military structures could emerge outside of NATO.
For the first time since the North Atlantic Treaty Organization (NATO) was founded in 1949, European leaders are seriously considering a future in which the U.S. is no longer their main military protector. With recent U.S. troop withdrawals from Germany and increasing pressure on allies to boost defense spending, Europe may need to build its own independent military capability.
Most Europeans have never known a world without U.S. involvement in NATO.
However, with President Donald Trump announcing he is considering withdrawing the United States from NATO, member nations may need to prepare for that reality.
Trump has faced harsh criticism from international allies by claiming that the U.S. “never needed” NATO and that alliance troops “stayed a little back, a little off the front lines” in Afghanistan, according to an article by CNN. He has also called the alliance a “paper tiger” and criticized its members after refusing to help the U.S. reopen the Strait of Hormuz during the Iran War.
NATO is an alliance formed to guarantee the freedom and security of its members through military and political means. Founded in 1949 in the aftermath of World War II, the alliance is comprised of 32 countries – 30 in Europe and two in North America. NATO operates under the fundamental principle of collective defense, which states that an armed attack against one member shall be considered an attack against all members. Since its founding, this principle has joined together a team of like-minded countries who have committed themselves to protecting each other in a spirit of solidarity and mutual aid.
NATO has provided more than 75 years of security to Europe and North America by ensuring economic, military and political benefits, according to the Atlantic Council. It prevents major regional conflicts, secures trade routes and provides a framework for international crisis management, offering stability and security for over 30 member nations.
NATO has served as a foundation for transatlantic security since its founding, according to NATO, and throughout its history, it has provided significant benefits, including during the Cold War, the 9/11 attack on the U.S. and the Russo-Ukrainian War.
A U.S. withdrawal from NATO would fracture the Western security architecture, removing the core military, intelligence and nuclear guarantee for Europe, according to the Center for Strategic and International Studies. For Europe, it would force a rapid, costly buildup of independent military capabilities; for North America, it would cause decreased global influence, high economic disruption and the potential loss of strategic foreign military bases.
Trump cannot unilaterally withdraw the U.S. from NATO without congressional approval, which requires a two-thirds Senate majority or an act of Congress, according to the 2024 National Defense Authorization Act. Though he may attempt to challenge this, legal experts argue that a formal exit is unlikely; however, he could significantly weaken the alliance by reducing military commitment, which is known as a “de facto” withdrawal.
If the U.S. were to withdraw from NATO, Europe would have to quickly establish a backup plan that would allow them to take responsibility for their own defense, according to the International Institute for Strategic Studies. Actions would include doubling down on defense spending, replacing U.S. intelligence and logistical assets and strengthening European nuclear deterrence by France and the United Kingdom.
Joshua Shifrinson, Associate Professor of International Policy in the School of Public Policy at the University of Maryland College Park, said a potential withdrawal from the United States would not pose the same threat to Europe today as it would have when the alliance was initially formed. “An American withdrawal has some really negative implications for some states, but for much of the continent, the impact is primarily political and primarily a matter of figuring out how they’re going to get along with each other going forward,” he said in an interview with Atlas Broadcasting.
Jim Townsend, Adjunct Senior Fellow in the Transatlantic Security Program at the Center for New American Security, said Europe will need to band together to ensure a strong military force without the United States. “[Europe’s] got to work closely together in a cooperative way to determine who should bring and how much to bring of the equipment that the U.S. would have provided,” he said in an interview with Atlas Broadcasting. “The U.S. has got to be more cooperative in terms of saying, ‘Look, we’ll stay here until you all can fill these gaps,’ but we’re not doing that and it doesn’t give the Europeans enough time to do what they need to do.”
Trump has not announced a formal decision to withdraw from NATO, but his administration is actively reducing U.S. forces in Europe. Following a May 1st announcement to withdraw 5,000 troops from Germany, NATO allies anticipate more significant troop drawdowns from Germany, Italy and Spain.
