Overview
In February 2026, US Undersecretary of War for Policy Elbridge Colby explicitly pushed for a “NATO 3.0”—one that returns the alliance to “hard-nosed realism” and European-led deterrence of Russia. This process appears to have already begun, with announced transfers of joint force commands from US leadership to European generals and the anticipated withdrawal of US servicemembers from NATO command installations. Moreover, the US has reportedly called for an end to “out-of-area” missions like the Kosovo Force, which may undermine a reassurance force in Ukraine. These debates will prime an intense July 2026 NATO Summit in Ankara. If unmanaged, the transition to a mostly independent “NATO Europe” could undermine the entire alliance. In any case, Europe may sprint to achieve independent “strategic enablers,” pursuing “Buy European” procurement policies and forming a European-led defense planning process. This would undermine the US’ ability to steer NATO’s strategy, doctrine, and operations.
Introducing “NATO 3.0”
At the mid-February NATO defense ministerial, Undersecretary Colby delivered remarks urging a NATO 3.0 alliance that returns the group to its original strategic purpose of deterrence. Colby portrayed the post-Cold War “NATO 2.0” as a morphed internationalist institution focused on capacity-building, stabilization through enlargement, and out-of-area operations (i.e., through peacekeeping and the Afghanistan intervention). Per this argument, NATO 2.0 became a kaleidoscope of strategic pillars that undermined its core deterrence function, as evident by Russia’s ambitions to reshape Europe’s security architecture through its invasion of Ukraine. Colby suggested that the modern geopolitical age compels Europe to take up “responsibility for its own defense” so that the US can focus on deterring China. In 2025, this transition began with NATO members and allies’ commitments to spend 3.5% of their respective GDPs on hard defense items by 2035. However, the transition to an independent “NATO Europe” will ignite tougher questions on institutional management.
While NATO’s bureaucratic politics take place behind closed doors, early signals ahead of the July summit suggest that the US seeks to institutionalize the transfer of operational management of NATO to the Europeans. In early February, NATO announced that, over the next few years, the UK will take over leadership of Joint Force Command (JFC) Norfolk and Italy will take over JFC Naples. The JFC leadership position reshuffle means that a British and an Italian four-star general will lead the planning and operations for a potential Europe-wide conflict, albeit in coordination with the Supreme Allied Commander Europe, a position still dual-hatted by the chief of US Europe Command. While Europe will eventually become fully responsible for the JFCs, the US will take over Maritime Command (MARCOM) from the UK, a lower yet vital operational command for NATO’s maritime operations.
This reshuffle, if well managed, may improve NATO’s operational cohesion and reflect a rearmed European force. However, the transition to Europe’s operational leadership may be abrupt, given that the US is reportedly declining to backfill up to 200 of 400 US service positions in various NATO installations once those positions expire. These positions span the NATO Intelligence Fusion Centre, Allied Special Operations Forces Command in Brussels, and Centres of Excellence, which help NATO allies integrate innovative technologies and tactics. Other allies could close the gap to ensure the functioning of these installations, but the lack of US ownership over those institutions could undermine American steering, undermining the US will to participate and potentially the institutions’ effectiveness. After all, forces follow leadership. If the US transfers joint force commands, then new European leaders will likely supply the troops and capabilities to execute planned missions. If the US does not lead NATO’s intelligence, surveillance, and reconnaissance (ISR) operations, then it may decrease its contributions to intelligence-sharing. As such, this seemingly bureaucratic change may compel the Europeans to scramble to expand independent “strategic enablers,” such as scalable defense industrial bases and space-based ISR, but those changes will require years of investment.
Implications of a NATO 3.0 for Defense Partnerships
Beyond the bureaucratic politics of the US ceding operational management, the US has also reportedly advocated for keeping the pact a strict European deterrence alliance, thereby ending out-of-area operations and consultations with external partners like Ukraine and Japan. Out-of-area operations are when NATO intervenes outside territory protected by Article 5 to fulfill a security role. These missions are typically approved by the UN Security Council and often include non-NATO military contributions under NATO’s command. The most prominent example is the International Stabilization Assistance Force (ISAF)—the NATO-led coalition to hold Afghanistan from 2001-2014—but there are also active missions in the Western Balkans (The Kosovo Force, or KFOR) and in the Middle East (through NATO Mission Iraq, or NMI).
To the proponents of NATO 3.0, ending out-of-area operations makes sense. From their perspective, these operations distract NATO allies and overemphasize expeditionary capabilities over conventional deterrence. Moreover, these missions—often focused on stabilizing a region (like ISAF or KFOR) or capacity-building in a non-combat role (like NMI)—are emblematic of NATO’s post-Cold War embrace of capacity-building. To the proponents of out-of-area operations, these missions serve as a multiplier for regional stability in active or frozen conflict zones, inter-military capacity-building and training, and institutional experience with multinational deployments.
The debate on out-of-area operations holds implications for Ukraine, which presumably would reduce or cease dialogue with NATO 3.0 outside of its application to eventually join. While US-led Russia-Ukraine peace talks simmered in February, the US and Europeans remain aligned that deploying a reassurance force would be a key dimension of any security guarantee to prevent reemerged conflict. The division of labor appears roughly spelled out, with Europe leading operations while the US provides “strategic enablers,” like ISR and airlift capability, to enable European troops on the ground. This mission would presumably benefit from a NATO command and control structure, but this remains unclear under NATO 3.0.
The upcoming July 2026 Ankara NATO Summit may provide the first high-level debate on the future of missions like KFOR and NMI. The most effective transition would include policy adjustments in a new Strategic Compass, given that the current iteration views conflict prevention as a strategic pillar on par with deterrence. The US may be satisfied with a simple reduction in force or may otherwise unilaterally withdraw its troops and commands if other allies do not agree to scale down these missions. This would provide an opportunity for NATO Europe to step in, although an effective transition to European-led command and control may test the missions’ endurance. Alternatively, the US may push to transfer management of these missions to the EU. This has historically occurred, most notably with the EU’s takeover of the Implementation Force (IFOR) in Bosnia, now called EUFOR. But a reduction in capabilities and strategic enablers would run into the same problem if the transition were unmanaged.
The Promise and Perils of NATO 3.0
The US seeks to accomplish two goals. On the one hand, it wants Europeans to step up in NATO’s management. On the other hand, the US wants to continue steering the alliance’s strategic direction and prevent a Europe-led defense actor from “delinking, duplicating, or discriminating” against the US-led security umbrella. These two things, while not mutually exclusive, present a trade-off. While a NATO Europe would be institutionally more feasible than, say, an EU Army, a NATO with less America would functionally achieve something similar. If the US were to remove itself from NATO management, the “American way of war” may be replaced by a “European” strategic culture, conventional capabilities, defense planning, or nuclear deterrent. The US would lose its ability to steer NATO’s strategy, doctrine, and operations.
The key question of NATO 3.0 is how much the US plans to withdraw capabilities from Europe. Under current law, the US cannot reduce troops below 76,000 without approval from Congress. Nonetheless, Congress may green-light a pivot to Asia under demanding circumstances. This could include removing all American rotational deployments from Europe, reducing the US posture to about 65,000 permanent troops. Under a more extreme scenario, a US withdrawal could mean removing all US conventional capabilities not required for the nuclear umbrella by 2027, including intelligence gathering. This is reportedly the preferred outcome from some senior Pentagon officials. Both scenarios will require faster action from NATO Europe in rearmament, a surge in defense industrial production, and a sprint for independent space-based ISR capabilities. This would likely occur under “Buy European” procurement policies, requiring American companies to enter joint ventures to access European defense markets.
Transatlantic distrust is already at a new low after the Greenland dispute, and this may be reinforced over the Iran war. European countries have criticized the legality and spillover risks of the US-Israeli intervention, especially since most leaders were not read in on the plans. Most European nations rejected calls from US President Trump to assist with restoring free navigation in the Strait of Hormuz, reinforcing Trump’s perception that NATO is not a reciprocal alliance, despite the Middle East being an “out-of-area” region unprotected from Article 5. Moreover, NATO European countries are anxious about air defense shortages resulting from the Iran war, which could create a material disadvantage for Ukraine on the battlefield.
Nonetheless, NATO 3.0 can be introduced without causing needless disruption. The realist principle behind the idea stands—the US cannot be everywhere all at once, and NATO may have to refocus its deterrent mission after Russia’s invasion of Ukraine—but execution is key. If NATO 3.0 leads to a more sustainable alliance, increased European operational readiness, and a surged European defense industrial base, then there are upside risks for efficient defense planning and achieving US national security objectives. Nonetheless, the devil is in the details, potentially setting up an intense debate that the 2025 Hague Summit deliberately side-stepped. The Alliance easily agreed to rearmament, but defense planning, timelines, and doctrine present more complicated debates for the 2026 Ankara Summit.
