The North Atlantic Treaty Organization (NATO) was formed in the aftermath of World War Two, and has since grown to include twenty-eight states in Europe and North America. NATO has often been credited with maintaining peace during the Cold War, but has recently come under fire from a number of world leaders, such as U.S. President Donald Trump.
“NATO is obsolete and must be changed,” Trump said in 2016, also claiming that the U.S. pays “a disproportionate share of the cost of NATO” and that “it is time to renegotiate!” While the President later revised his position in favor of the alliance, the recent surge of anti-NATO sentiment poses an interesting hypothetical:
What if the U.S. left NATO?
To understand the repercussions of this on the world stage, we must first understand the impact the alliance has had throughout its 68-year history. The North Atlantic Treaty was signed in 1949 by ten European states, along with the United States and Canada, as a provision against the threat posed by the Soviet Union. While some criticized the treaty as a neocolonial attempt by America to further extend its reach and provoke war with the Russians, NATO played a key role in ensuring that the Cold War never escalated. At the heart of this Pax Europa is Article V of NATO, which states that an attack on one-member nation is an attack on them all. This guaranteed to the Soviet Union that any military action against western Europe would be met with a potential nuclear strike by the United States; maintaining the doctrine of Mutually Assured Destruction (MAD), which protected the world from a nuclear war between the two superpowers.
The U.S. leaving NATO would be a significant blow for the alliance. With a defense expenditure of $664.1 billion for the 2016 fiscal year (3.6% of the U.S. GDP), the U.S. contributes roughly 72% of the alliances’ total budget. Without this support, the operational capacity of NATO would be greatly reduced. The alliance would also lose the use of nearly 800 U.S. military bases across the globe, further reducing NATO’s projection of power.
Without the guarantee of American protection, the European member states would likely attempt to mitigate the loss by other means. Many of the largest NATO members, such as Germany, France, and the UK, have begun increasing their defense spending. These three nations would also presumably take over command of the alliance, while likely extending membership to non-member states, such as Ireland and Austria.
22 of NATO’s 28 members (all but the U.S., Canada, Turkey, Albania, Iceland and Norway) are also members of the European Union. With such a great overlap in membership between the two organizations, an American withdrawal would likely see NATO and the E.U. functioning much more closely. The formation of a European army has been a matter of great contention within the E.U. If the U.S. were to pull out of NATO, it might sway some of the opposition to the belief that an E.U. army would be a necessary safeguard against prospective threats.
Possibly the greatest strength of NATO is not its actual defense capabilities, but rather the deterrent it poses to Russia, who has set its sights on regaining the territory it lost with the fall of the Soviet Union; most recently with its annexation of Crime. Russia has also shown interest in the Baltic states of Lithuania, Latvia and Estonia. However, the situation there has not yet escalated, because of Article V retaliation, as all three are NATO members. Without the U.S. in NATO, Russia would likely be emboldened to make more attempts at territorial gain, though none as audacious as the annexation of the Crimea. Although weakened, NATO would still pose a serious threat to Russia, as both the UK and France have nuclear arsenals, deterring a potential attack. Instead, Russia would likely support friendly insurgent groups in European countries, as it has in Ukraine.
No one can know with 100% certainty the effects of the U.S. leaving NATO. Such an event would change the geopolitical landscape in likely unforeseen ways. What is clear, however, is that a lack of United States involvement would unify Europe. Although, a unified Europe may not be strong enough to counter Russian aggression.