Why NATO Needs Ukraine
Has the United States decided to fold it's "nuclear umbrealla" that most of Europe has depended upon to shield it against aggression from Russia?
An Uncertain Future of European Security
The North Atlantic Treaty Organization (NATO) was founded in 1949 to contain Soviet expansion and ensure European security under an American nuclear umbrella. While European nations, apart from Britain and France, lacked independent nuclear capabilities1, the U.S. provided the alliance’s military backbone. Britain played an outsized diplomatic role, largely due to figures like Lord Ismay, NATO’s first Secretary General, who famously described its purpose: “to keep the Russians out, the Americans in, and the Germans down.”
From its inception, NATO has navigated internal divisions—France’s nuclear ambitions, perpetual burden-sharing disputes, and tensions over American dominance—while successfully deterring Soviet aggression. After the collapse of the Soviet Union in 1991, the alliance expanded eastward, integrating former Soviet states into the European Community and NATO as well as committing to new ‘out-of-region’ security challenges beyond Europe, such as Iraq and Afghanistan. However, this expansion fueled Russian resentment, setting the stage for renewed confrontation.
Russia’s Playbook: Influence, Invasion, and Annexation
With the Soviet Union’s collapse, newly independent states, including Ukraine, sought closer ties with Europe. Ukraine, in particular, gave up its nuclear arsenal under the Budapest Memorandum, receiving security assurances from the U.S., UK, and Russia—assurances that would later prove hollow.
Author’s note: Previously, Ariadne examined the risks of resuming strategic nuclear weapons testing at a time when the existing START treaty is set to expire with no framework in place for renewal (Dismantling the Big One). A future piece will explore nuclear force modernization—how it fits within an initiative to significantly reduce U.S. and Russian arsenals—and separately, the potential for a broader European nuclear deterrent that could include countries beyond France and the UK, possibly including Ukraine. A topic that is drawing new attention.
This month, a two-part newsletter examines NATO and Ukraine’s role in European security. The second newsletter examines the military command structure of NATO and the diminishing role of the American Supreme Commander Allied Powers Europe (SACEUR), which the US is reportedly considering abolishing.
While Ukraine’s military resilience has surprised many, its strategic importance remains underestimated—except by a U.S. administration seemingly intent on improving relations with Russia. As NATO reassesses its future, Ukraine’s place within European defense structures is becoming impossible to ignore. Consider for a second where we would be today if Ukraine had succumbed to Russia’s invasion.
Next month, Ariadne steps away from geopolitics to explore an overlooked chapter in ocean exploration. In the 1950s, underwater habitats were envisioned as the next frontier of human settlement, but instead, scuba diving evolved along a very different path. This upcoming piece (Living Underwater) will examine how early ambitions of living beneath the sea gave way to the reality of recreational diving and deep-sea research.
Russia, under Boris Yeltsin, began a period of growth for corruption and oligarchies that arose out of the denationalization of industries and resources. Additionally, Russia launched extensive electoral interference, disinformation, and economic leverage, particularly in Belarus, Georgia, Moldova, and Ukraine. Vladimir Putin inherited and expanded this strategy, determined to reassert Russia’s dominance over its former sphere of influence.
The 2008 invasion of Georgia demonstrated Putin’s willingness to use military force, but the West’s muted response—combined with European reliance on Russian energy—convinced him of NATO’s weakness. In 2014, Russia illegally annexed Crimea, exploiting Ukraine’s political turmoil and NATO’s reluctance to intervene. Putin’s calculation: preventing NATO expansion justified any cost. Western sanctions followed but failed to deter further aggression. 2
Russia, under Boris Yeltsin, began a period of growth for corruption and oligarchies that arose out of the denationalization of industries and resources. Additionally, Russia launched extensive electoral interference, disinformation, and economic leverage, particularly in Belarus, Georgia, Moldova, and Ukraine. Vladimir Putin inherited and expanded this strategy, determined to reassert Russia’s dominance over its former sphere of influence.
The 2008 invasion of Georgia demonstrated Putin’s willingness to use military force, but the West’s muted response—combined with European reliance on Russian energy—convinced him of NATO’s weakness. In 2014, Russia illegally annexed Crimea, exploiting Ukraine’s political turmoil and NATO’s reluctance to intervene. Putin’s calculation: preventing NATO expansion justified any cost. Western sanctions followed but failed to deter further aggression.Thanks for reading Ariadne! Subscribe for free to receive new posts and support my work.
The Shifting American Commitment
Recent remarks by U.S. officials at NATO summits and the Munich Security Conference have shaken European confidence in American commitment to continental defense. Washington’s strategic pivot to Asia, focused on countering China, signals a shift in priorities. Meanwhile, the U.S. administration’s ambiguous stance toward Russia leaves European allies uncertain about America’s long-term security role.
Despite these uncertainties, Ukraine has demonstrated military expertise that European nations cannot afford to ignore. Like Churchill’s plea to Roosevelt—“Give us the tools, and we will finish the job”—Ukraine’s fight has reshaped perceptions of European security. The war has also exposed NATO’s continued reliance on American intelligence, even as trust in U.S. intelligence assessments has waned after repeated failures over the past decade.3
Europe’s Moment of Reckoning
European nations must now confront a fundamental question: Can they continue to depend on America’s nuclear umbrella and military leadership? The credibility of the American security guarantee—a cornerstone of NATO for over 70 years—is now in doubt. France and the UK, Europe’s independent nuclear powers, may need to assume greater responsibility for Europe’s nuclear deterrent posture.
Moreover, Europe’s economic and security architecture cannot exclude Ukraine. With thousands of kilometers of direct contact with Russia, Ukraine is no longer just a buffer state—it is a frontline European power. When and how Ukraine is integrated into the European Community as well as NATO is the issue; Ukraine’s role in the alliance is now indispensable. 4
Beyond Russia: NATO’s Global Challenge
While Russia remains NATO’s immediate concern, China’s rise presents a broader challenge. Beijing’s economic and technological influence in Europe, combined with its growing military partnership with Russia, signals a shift toward a more coordinated authoritarian bloc. NATO’s response to this evolving threat remains uncertain. Should the alliance maintain its Euro-Atlantic focus, or should it expand its mission to counter China’s influence?
The Path Forward
NATO has survived Cold War crises, internal divisions, and shifting strategic priorities. Yet, its future depends on its ability to evolve. The alliance must:
1. Strengthen European Defense Autonomy: A more self-sufficient European defense capability is essential, particularly if U.S. priorities continue shifting toward Asia.
2. Fully Integrate Ukraine into European Economic and Security Affairs: Whether this is to be made as an incremental approach beginning with conditional membership of the European Community and with varied security arrangements prior to full NATO membership, Ukraine’s role in European defense is now undeniable.
3. Adapt to a Multipolar Security Environment: NATO must reconcile its core mission with emerging global threats, including China’s growing influence.
The question facing NATO today is not just about military readiness—it is about political will. Europe must decide whether to take greater control of its own security or remain tethered to an increasingly uncertain American commitment. One thing is clear: the underestimation of Ukraine should serve as NATO’s final wake-up call.
Following the U.S. Vice President’s remarks at the February 2025 Munich Security Conference, there has been renewed debate on Europe's—and Ukraine’s—role in a potential independent deterrent. This subject will be explored further in a future issue of The Ariadne Dispatch. For a summary of the issues see:
Michaels, Daniel, Bisserbe, Noemie, Gordon,Michael R., Trump Prompts European Calls for a Homegrown Nuclear Umbrella, The Wall Street Journal, March 24, 2025
At the time of the Soviet Union’s dissolution, Ukraine inherited the world’s third-largest nuclear arsenal, which would have made it the largest nuclear weapons power in Europe. In it’s 1990 Declaration of State Sovereignty, Ukraine stated that it would not accept, acquire, or produce nuclear weapons, and its government declared on 24 October 1991 that Ukraine would be a non-nuclear-weapon state. Under the 1994 Budapest Memorandum, Ukraine agreed to relinquish these weapons in exchange for security assurances. Since then, Ukraine has maintained one of the most extensive nuclear energy programs globally and retains deep technical and doctrinal knowledge of the Russian nuclear enterprise—ranging from weapons design to the strategic philosophy underpinning Russian targeting and operational planning. This makes Ukraine a potentially vital participant in any future European nuclear deterrent framework, even without directly deploying or developing nuclear weapons. While France and the UK maintain independent deterrents, the UK’s system is notably integrated with the US, particularly through it’s use of US Trident submarine ballistic missiles. Tactical (lower explosive yield) nuclear weapons need not be part of a European posture; their absence would not preclude credible deterrence or strategic independence from the U.S. nuclear umbrella.
Putin’s War in the Ukraine: A conversation with Fiona Hill and Angela Stent, Talbot Papers, Brookings Institution, September 19, 2022
Kasparov, Gary, Ukraine Needs NATO—and NATO Needs Ukraine Too, The Bulwark Online, July 11, 2023