As NATO leaders prepare to convene this week in Ankara, the alliance faces significant challenges amid evolving geopolitical dynamics and internal tensions, particularly concerning the United States’ commitment and Turkey’s shifting role within the organization.

Since taking office, NATO Secretary General Mark Rutte has focused heavily on maintaining U.S. engagement with the alliance, especially in light of President Donald Trump’s repeated criticisms and threats to withdraw American support. Trump’s initial grievances centered on European allies’ military spending, but following their commitment last year to match U.S. defense investments relative to GDP, attention has shifted to the effective conversion of funds into military capabilities. Rutte recently presented Trump with a chart dubbed “The Trump Trillion,” highlighting $1.2 trillion in defense spending by European allies and Canada since 2017 to emphasize their contributions. However, the U.S. president remains unswayed, expressing dissatisfaction over NATO countries’ reluctance to back the U.S.-led campaign against Iran, which he initiated alongside Israel without allied consultation. Trump has underscored loyalty over financial contributions, and his participation in the summit was attributed largely to the event being hosted by Turkish President Recep Tayyip Erdogan.

Turkey’s stature in NATO has notably increased going into the summit. Once viewed with suspicion by some member states due to its purchase of a Russian S-400 air defense system, military actions against Kurdish forces in Syria, and opposition to Sweden’s NATO accession, Ankara is now leveraging its robust domestic arms industry and strategic position. As NATO seeks to bolster collective defense amid concerns over Russian aggression in Eastern Europe, Turkey’s military—NATO’s second-largest—and control over the Bosphorus Strait serve as pivotal assets. The summit is also expected to spotlight Turkey’s growing defense production capabilities, which European nations are increasingly relying on amid U.S. sporadic troop withdrawals and growing regional instability.

Trump’s rapport with Erdogan is a key factor in the U.S. president’s summit agenda. Trump has publicly praised Erdogan as a “friend” and a “hell of a leader,” noting that without Erdogan’s hosting, he might have skipped the meeting altogether. This cordiality contrasts with Trump’s often contentious dealings with other European allies. For Ankara, Trump’s attendance and commendations represent a significant diplomatic win, which Erdogan is poised to utilize for domestic political capital. Further, Trump has indicated potential progress on longstanding disputes with Turkey, including possible sales of F-35 fighter jets and aircraft engines, matters previously stalled after the S-400 purchase.

Despite this improving bilateral dynamic, underlying tensions persist. Turkey’s relations with Russia remain complex, marked by both cooperation and opposition, as seen in Ankara’s drone sales to Ukraine amid the ongoing Russia-Ukraine conflict. The summit will feature meetings between Trump, Ukrainian President Volodymyr Zelenskyy, and Syrian President Ahmad al-Sharaa, with discussions expected to focus on conflict resolution efforts and regional security.

European allies, while seeking to present a united front, have muted criticism of Turkey’s democratic backsliding and human rights record ahead of the summit. Recent crackdowns in Turkey have led to the detention of over 200 individuals, including political activists and academics, raising concerns among rights groups. However, as Ankara positions itself as an indispensable defense partner and gatekeeper for European security, many European officials have deprioritized these issues to maintain strategic cohesion. This pragmatic stance has drawn criticism from Turkish opposition figures and analysts, who warn that the alliance’s focus on military priorities risks sidelining fundamental values.

Turkey’s strained relationship with the European Union adds another layer of complexity. While ties have warmed with some EU member states, Ankara’s longstanding EU accession bid remains stalled, complicated by disputes over territorial waters and political disagreements. Turkish officials are increasingly pursuing bilateral defense agreements with individual European countries, further reflecting the evolving nature of its partnerships.

As NATO convenes amid these multifaceted challenges, the alliance’s ability to reconcile divergent national interests, sustain U.S. commitment, and integrate Turkey’s enhanced military role will be critical to its cohesion and effectiveness in addressing global security threats.