Key Points – While NATO supports Ukraine’s self-defense against Russia and is not a direct belligerent, the risk of the conflict escalating into a NATO-Russia war persists.
-Moscow consistently frames the war as a confrontation with the West and has issued nuclear threats.
-The most likely triggers for a wider conflict are not a premeditated Russian attack on NATO—which would likely require Chinese support Russia may not get—but rather an accidental escalation, such as Russian missiles or aircraft straying into NATO territory.
-A US withdrawal from NATO under President Trump would also dramatically increase Europe’s vulnerability, creating a decades-long window where the continent would struggle to replace American military capabilities.
Welcome to World War III: A NATO-Russia War over Ukraine?
The Russia-Ukraine war has, from the outset of the full-scale invasion of Ukraine in February 2022, been framed by Moscow as a confrontation not just with Kyiv, but with NATO itself.
In February 2023, Russian President Vladimir Putin accused NATO of actively participating in the war in Ukraine, asserting that the alliance’s provision of “tens of billions of dollars in weapons” to Ukraine amounted to direct involvement.
Russian Foreign Minister Sergey Lavrov had already made that point months earlier in December 2022, stating, “You shouldn’t say that the U.S. and NATO aren’t taking part in this war. You are directly participating in it,” in reference to the training of Ukrainian military personnel on NATO member territories.
Despite Russia’s warnings, however, NATO countries have maintained that the Ukraine-Russia conflict does not constitute a NATO-Russia war, and that NATO supports Ukraine’s right to self-defense as enshrined in the United Nations charter.
While NATO countries have provided substantial military and financial aid to Ukraine – so much, in fact, that the conflict would have ended with a Russian victory long ago without it – they have refrained from themselves deploying troops or conducting strikes directly against Russian forces. However, the potential for escalation remains, especially if diplomatic efforts falter. In May 2024, President Putin warned that allowing Ukraine to use Western-supplied long-range missiles to strike deep into Russian territory could escalate the conflict into a global one, cautioning European countries about the consequences.
Further heightening tensions, in May 2025, Deputy Foreign Minister Alexander Grushko responded to NATO military exercises in Lithuania by asserting that Russia would take measures to “neutralize” all alliance efforts perceived as threats.
Worse, Deputy Chairman of Russia’s Security Council, Dmitry Medvedev, has issued multiple threats against NATO countries. In November 2023, Medvedev warned that Poland risked “losing its sovereignty” and suggested that Moscow might be willing to reclaim territories given to Poland after World War II. Medvedev also explicitly threatened nuclear strikes on Western capitals, including London. In February 2024, he stated that if Russia were forced to return to its 1991 borders, it would lead to a global war involving the use of Russia’s entire strategic nuclear arsenal against cities including Kyiv, London, Berlin, and Washington.
“Attempts to return Russia to the borders of 1991 will lead to only one thing—a global war with Western countries with the use of our entire strategic (nuclear) arsenal,” Medvedev said at the time.
While Medvedev is widely considered to be Putin’s “attack dog,” making statements the Russian president cannot, the consistency and severity of these threats mean that a conflict between Russia and NATO is not officially off the cards. The question is not whether such a war could happen, but what might trigger it.
What Could Trigger A NATO-Russia War?
A NATO-Russia war could, in theory, be prompted by Russian frustration with Western support for Ukraine, prolonged conflict in the country, or desperation. However, prolonged conflict will continue to weaken Russia, meaning a decision to launch an attack on NATO territories, and thereby trigger a global conflict, would undoubtedly require the backing of Russian allies.
China, Russia’s largest and most powerful ally, might be hesitant to provide it. The country would be dramatically impacted by a global war involving NATO and BRICS countries, and is already working diligently to secure favorable trade conditions with the United States after President Donald Trump slapped unprecedented tariffs on imports from the country. While trade conditions between China and the U.S. are nowhere near as beneficial to China as they were previously, they would likely be significantly worse if NATO, whether that includes the U.S. or not by the time a hypothetical conflict were to occur, were at war with Russia.
Russia would arguably not only require China’s political support, but its manpower, military prowess, and industrial capabilities to sustain such a large conflict.
With this in mind, it seems clear that a Russia-NATO war is more likely to be caused by an accidental Russian attack on NATO territory or assets, or a minor deliberate incursion designed to serve as a threat.
Such a scenario is not only possible, but has occurred before. In May 2025, Russia warned that it would defend its ships in the Baltic Sea “with all means available” after Estonia attempted to seize a Russian-bound oil tanker. A Russian fighter jet, in the process of defending the ship, reportedly violated NATO airspace during the incident.
In December 2024, during a Russian missile attack on Ukraine, a Russian missile entered Polish airspace for approximately three minutes before it returned to Ukrainian territory. The missile traveled about 40 kilometers into Poland, prompting an activation of NATO and Polish fighter jets, as well as a formal diplomatic protest to Russia. Later, in March 2024, a Russian cruise missile again briefly violated Polish airspace near the village of Oserdów, staying for 39 seconds before re-entering Ukraine. Poland demanded an explanation from Russia and activated its air force in response, but it did not result in an exchange of fire.
The incidents, much like the November 2022 fatal missile strike in Przewodów, in which a Ukrainian S-300 air defense missile is believed to have caused the deaths of two Polish citizens, were clear accidents. Nonetheless, the proximity of NATO countries to Russian and Ukrainian borders – a fact that is itself relevant to the origins of this conflict – means more accidents are likely to occur in the future. Some of those accidents may once again prove deadly, and as relations between NATO countries and Russia continue to deteriorate, there’s no telling what militaristic reactions there may be to the next cross-border incident.
This will prove to be a particularly worrisome scenario for Europe in the event that President Donald Trump follows through on repeated implied threats that the United States may withdraw from NATO.
Europe Is Vulnerable
As I reported on May 20, Europe remains dangerously exposed to Russian aggression, especially if the United States does follow through on threats to withdraw from NATO. President Trump hasn’t explicitly committed to leaving the alliance, but his repeated skepticism and stated willingness to make dramatic changes means such a scenario should not be ruled out at this stage.
Should Trump both pull the plug on support for Ukraine and backing for NATO, the burden of resisting Russian advances would fall squarely on European shoulders. That alone could shift the balance of power and embolden Russia, particularly if Moscow senses hesitation or weakness among NATO’s remaining members.
A study published by the International Institute for Strategic Studies (IISS) on May 15 2025 outlines the stakes. According to the IISS, a full U.S. withdrawal would create a 25-year “window of vulnerability” for Europe, during which time the continent would struggle to replace the loss of American military personnel and hardware, leaving NATO exposed to a potential Russian offensive as early as 2027.
Russia’s ground forces, the report notes, could rebuild to 2022 levels within just a few years. Meanwhile, Europe would face massive shortfalls, losing up to 128,000 troops as a result of U.S. departure, as well as large gaps in air, maritime, and surveillance capabilities. In some areas, like stealth aircraft and rocket artillery, Europe doesn’t even have the capacity to produce replacements without major foreign help or a complete industrial overhaul.
Europe’s defense industry isn’t ready, either. While land sector procurement has picked up, naval and aerospace sectors remain sluggish. Financing gaps, labor shortages, and regulation only add to the dysfunction. Even if Europe accelerated investment today, it wouldn’t be capable of fully replacing U.S. military contributions for at least a decade.
That industrial weakness could also force European states to buy more from foreign suppliers, undermining their strategic autonomy. And, the more reliant Europe becomes on third parties for arms and ammunition, the more likely it is to face diplomatic pressure – and restrictions – based on the interests of those suppliers. That risks weakening the continent’s transatlantic ties and could compromise military readiness in a future crisis.
Even the United Kingdom, traditionally one of Europe’s strongest forces, is struggling. As of early 2025, the British Army has just over 73,000 regular soldiers and fewer than 25 operational Challenger 2 tanks. A new fleet of Challenger 3 tanks is on the way, but may not be fully serviceable until 2030.
So while a NATO-Russia war remains unlikely for now, a major shift – such as the U.S. walking away from NATO – could change that. For Moscow, it might be the opening it needs, if war with NATO is indeed something President Vladimir Putin considers to be in Russia’s strategic interests.
About the Author:
Jack Buckby is a British author, counter-extremism researcher, and journalist based in New York. Reporting on the U.K., Europe, and the U.S., he works to analyze and understand left-wing and right-wing radicalization, and reports on Western governments’ approaches to the pressing issues of today. His books and research papers explore these themes and propose pragmatic solutions to our increasingly polarized society. His latest book is The Truth Teller: RFK Jr. and the Case for a Post-Partisan Presidency.
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