NATO at the Crossroads: The Shifting Priorities of the United States, the Division of Europe, and the Collapse of the Common Threat Perception

NATO is the longest-standing and most institutionalised military alliance in modern history. After the Cold War, the alliance continued to exist for a while based on the formula of ‘common threat – common defence’, but later set itself new missions such as democratisation and stability-building for expansion. However, today NATO has become a structure that, perhaps for the first time in history, cannot unite around a common threat definition.

This rupture stems not only from the proliferation of direct military risks, but also from multidimensional factors such as the shift in US global priorities, Europe's security–economy dilemma, historical memory differences among members, and the invisible effects of the defence industry on security perceptions.

NATO is no longer merely a military alliance; it has begun to project an image as a political platform where different threat dossiers are negotiated. Consequently, the future of the alliance has become increasingly questionable. Although many scenarios are being discussed, the answers to two critical questions will determine the future of the alliance. Is there a common threat? How are the changing priorities of the US affecting the alliance? In this article, I have attempted to emphasise the fact that what has brought NATO to a crossroads today is not the increase in external threats, but the fragmentation of threat perceptions.

The US's Changing Strategic Priorities: The End of the Europe-Centred Era

Before moving on to the first question, it would be more accurate to clarify the second question. This is because the answer to the first question is actually hidden within it. The development that sparked recent discussions on this topic was the US National Security Strategy document published on 4 December 2025. The previous document foreshadowed these developments, but it did not generate sufficient debate because it did not contain such clear and direct statements. This document is the clearest expression of the transition from the world order that followed the Second World War, which was first bipolar and then unipolar under US hegemony after the collapse of the USSR, to a multipolar world. The United States, NATO's largest military power and political driver, has now clearly set its course, declaring that the main arena of competition is not Europe but the Asia-Pacific.

Accordingly:

• China is a ‘long-term strategic rival’ and the primary threat with the ability to reshape all elements of US national power.
• European security is ‘important but secondary.’ Russia has been identified as a ‘near and visible threat.’ In other words, China is the existential threat for the United States.
• For the United States, NATO is no longer a ‘security umbrella’ committed to the Western Hemisphere, but has begun to become a geopolitical tool that can be used according to its interests.

This shift has shocked Europe and heightened concerns about NATO's future. The source of concern is Europe's continued heavy dependence on the US for its own security, coupled with the US's desire to reduce this dependence. This situation also signals a development that will lead to a leadership vacuum in the alliance. Because Europe is not in a position to take on the leadership role. Of course, the question of which Europe comes to mind.

The US's gradual withdrawal from European security stems not from a political choice of the Trump administration, but from a structural necessity. With this change, Washington is shifting its strategic focus from Europe to the Asia-Pacific, based primarily on the shift in the balance of power caused by China and the global south. This orientation stems not only from a change in the perception of threats, but also from the fact that American military, economic and technological power has lost its capacity to maintain undisputed superiority on two fronts simultaneously. Consequently, the disappearance of NATO's ‘common threat’ concept is directly linked to the weakening of the United States' historical role within the alliance. After briefly summarising the US's situation, we can return to the first question:

Is There a Common Threat? Why Has the Perception of Threat Begun to Diverge in NATO?

The existence of a threat is the most important factor in reducing differences between members and strengthening ties, enabling a military alliance to survive. Initially, it was not difficult to establish a common perception of threat in NATO against dangers such as the spread of communism and nuclear weapons. After the Cold War, terrorism, migration, organised crime and, for the last three years, the Russian threat have come to the fore. However, these do not suffice to create a common view among all members as before. The fundamental reason for this is that each member interprets its own security environment through different variables. As the number of members has increased, so have the differences in opinion. In its most current form, Russia is seen as an existential threat by Eastern European members, while Western members share the same perception. The main threat for the US is China, while the agenda for members in the southern flank is uncontrolled migration, energy and Mediterranean security. Turkey's focus, on the other hand, is on the dangers arising from terrorism and regional instability.

To better understand the reasons for this divergence, we can draw on an analytical approach used in security theories. In short, the formula Threat Perception = Capabilities × Intent × Proximity × Sensitivity is an approach that helps explain how perception is formed according to different variables.

• Capabilities: The military power of the actor posing the threat
• Intent: Behaviour, objectives, and willingness to use this power
• Proximity: Geographical proximity or distance from the source of the threat
• Vulnerability: Refers to the military, economic, and political defencelessness of the target country.

For example, applying this formula to the threat posed by Russia's conventional military power provides a clearer understanding of how countries in the region perceive the threat.

• According to the Baltic countries, Russia's military power is excessive, its intentions are aggressive, it is very close to the border, their own defence capabilities are limited, and their vulnerability is high, with the traces of the past still vivid. From their perspective, it is an existential threat.
• For Germany, the opposing side's military power is high, its intentions are negotiable, it is not very close in terms of distance as there are countries that could act as a buffer, and economic relations create greater sensitivity. It is a high-priority but manageable threat.
• For Portugal, the military power is high but the distances are far, the intention to use that power against it is low, and the sensitivity is low, resulting in a second-priority threat.

In this example, the perception indicated through Portugal also points to the situation experienced during the Cold War. Member countries were forced to accept threats that they did not perceive as directly targeting them under the responsibility of the alliance. In other words, these are imported threats. In this context, it can be said that NATO partially maintained its existence in the post-Cold War period against these threats according to US security priorities.

As in the situation that arises from the adaptation of the formula above, countries assess the same threat differently from their own perspectives. In my opinion, another variable that should be added to this formula is Historical Memory. This alone is a multiplier that can change the perception of threat. The traumas experienced by countries, the traces of past conflicts, age-old hostilities, and the contributions of the social memory formed through these to the perception of threat cannot be ignored. For European countries that have experienced conflicts with each other throughout history, this factor is at least as important as the others.

When it comes to historical memory, it is necessary to mention the role of the United States as well as the traces left by the Soviet Union. According to the prevailing view, NATO's security and the political integration achieved through the EU are cited as the sources of the period of peace that Europe has enjoyed over the last 75 years. However, considering the conflicts and mistrust among European countries, the fact that long-term peace cannot be achieved without a security provider from outside the continent should not be overlooked. Therefore, it is more accurate to say that the real source of stability comes from US leadership.

Contrary to popular belief, it is not the economy that made EU integration possible, but rather the freezing of historical rivalries within Europe under the security umbrella provided by the US. In a way, NATO's existence has also facilitated the establishment of the EU. This is because member states have transferred their political sovereignty to a superstructure but have not transferred their security to it. Therefore, Europe did not produce this peace on its own. This stability is a result of the security provided by the external power, the United States. This is why the shift in US strategic priorities has caused such consternation. This change and the resulting concerns are the main factors accelerating the collapse of Europe's perception of a ‘common threat’. This development is a risk factor that could shake the political foundations of the EU.

A Unifying Exception Amidst Divergent Perceptions of Threat: The Nuclear Threat

While the assessment and perception of conventional threats can be explained by the formula mentioned above, the perception of nuclear threats is different. The distance factor disappears, affecting everyone indiscriminately and creating sensitivity. Intent is unclear, and the threshold for use is high. Therefore, for most countries, it is an abstract risk and does not take precedence over daily security priorities. Moreover, it has the effect of increasing dependence on the US. In this context, the nuclear threat can be considered a unifying but limited exception within NATO. It creates a common fear but does not suffice to produce a common strategic direction.

The Politicisation of Threat Perception: The Economic Dimension of the Defence Industry and Security Discourse

Within NATO, not only geopolitical developments but also the structural effects of the defence industry are decisive in shaping threat perceptions. The defence industry has become not only a result of security policies but also an increasingly influential actor. This situation is a contemporary reflection of the concept of the ‘military-industrial complex’ warned about by a US president in 1961.

Particularly following the Russia-Ukraine war, the rapid increase in defence spending among NATO countries demonstrates that threats are defined not only through objective risks but also through political and economic incentives. Threat rhetoric has become a powerful tool for increasing defence budgets, legitimising new weapons systems, and reducing public resistance to military spending. The symbiotic relationship between the defence industry and political decision-makers is causing the threat narrative to become even more politicised.

Therefore, the influence of the defence industry is at the heart of the crossroads NATO finds itself at. This effect is increasingly blurring the line between the reality of threats and the narratives of threats, making the alliance's long-term strategic alignment more difficult.

Europe's Security Dilemma

Europe expects the US to provide leadership in ensuring its security, while wanting to sustain its economy with China, the US's main rival. It expects the EU to provide political unity, while also wanting NATO to provide deterrence for this unity. This structure of multiple dependencies makes it difficult to develop comprehensive strategies within NATO without a leading power.

In such an environment, the discourse of ‘strategic autonomy’ spearheaded by France will not materialise without building the military capacity to shoulder its own security burden.

Conclusion: NATO's Real Crisis Is Not External, But Internal

Europe has progressively lost its capacity to generate security in the post-Cold War era. The nuclear protection umbrella provided by the US, its military technological superiority and geopolitical leadership have prevented European states from developing their own strategic independence. Today, their capacity to define threats and develop institutional strategies against them is limited. Their inability to act as an independent actor in the field of security is also deepening divisions within NATO.

NATO's expansion has not strengthened the alliance. The addition of new members with different historical memories, security priorities and political regimes has complicated threat definitions and decision-making processes.

The war in Ukraine initially created rapid and visible unity within NATO. However, over time, serious differences of opinion have emerged regarding the cost of the war, the risks it poses, and how it should end. Differences of opinion with the US, in particular, have deepened. For this reason, rather than being a unifying force, the war has made internal divisions within NATO visible. This division is expected to become even more pronounced in other conflict areas that are expected to emerge in the near future. This will call into question NATO's very raison d'être.

Today, the greatest threats facing NATO are Russia and China. As has been stated, they are not terrorism, migration or energy risks. The real danger lies in the alliance's inability to identify a common threat that would ensure its strategic cohesion, which is currently unravelling. The attempt to accommodate different security priorities is distancing NATO from its image as a military bloc. The crisis NATO is experiencing stems not from the physical military power capacity and the intention to use it, which are elements that shape the perception of threat, but from the differences in perception created by historical memory, sensitivity and proximity factors.

In this situation, the most fundamental question for the survival of a military alliance comes to the fore. In which conflicts can NATO truly act together? We can say that the likelihood of acting together is low in conventional threats and higher in situations involving the nuclear threshold.

Before concluding this article, the question that comes to mind is what the implications of these developments might be for Turkey. I would like to conclude this article by touching upon some points that I consider important for this topic, which warrants another article.

In the new era, Turkey's position has become both a strategic asset and a subject of political debate for the alliance. It is opening up space for strategic autonomy. It should continue to pursue multi-faceted policies as it has been doing.

It should not blindly comply with the alliance's policies but should not hesitate to resist where interests diverge. It should be a country that advocates its own security priorities more vocally within the alliance.

At a time when NATO is struggling to define common threats, Turkey's years of experience with multidimensional threats is a strategic advantage for itself and the alliance.

It should continue to develop its defence industry both to alliance standards and to different standards that will increase its competitive edge.

Note: The formula ‘Threat Perception = Capability x Intent × Proximity × Sensitivity × Historical Memory’ used in this study is a model developed by compiling various factors used in international security approaches. The basic components of the formula are derived from Stephen Walt's ‘Threat Perception / Balance of Threat Theory’ (1987) approach, while the sensitivity and historical memory multipliers are inspired by the Copenhagen School's securitisation literature (Buzan, Wæver & de Wilde, 1998).