Before Ankara, there was Istanbul. On 28 and 29 June 2004, NATO's leaders met on the Bosphorus for the first summit the alliance ever held in Türkiye, and much of what they decided there still shapes the alliance that lands in Ankara in July 2026.
The Istanbul of 2004 was a different NATO. It had just made the largest enlargement in its history: seven countries, Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia, joined that spring, taking the alliance to 26 members. And it was three years past the 11 September 2001 attacks, deep into the out-of-area, counterterrorism era that the summit's own agenda reflected.
What Istanbul decided
The headline decision was Afghanistan. NATO agreed to expand the International Security Assistance Force beyond Kabul, and with President Hamid Karzai in the room, the leaders named Afghanistan the alliance's top priority and pledged not to let it slide back into a haven for terrorists.
Iraq came next. A year after the 2003 invasion, the allies agreed to help train the new Iraqi security forces, the decision that created the NATO Training Mission in Iraq. Türkiye, which had kept its own troops out of the 2003 war, hosted the summit that put NATO's name to the training effort.
Then came the piece with the longest afterlife: the Istanbul Cooperation Initiative. NATO used the summit to open structured security partnership with the Gulf, starting with the Gulf Cooperation Council states. The alliance also deepened its Mediterranean Dialogue and wound up its SFOR peacekeeping mission in Bosnia, handing it to the European Union.
Taken together, it was the summit of a NATO reaching outward, crisis management, training missions, partnerships far from its own borders, the phase that a round-number shorthand now calls NATO 2.0.
Türkiye as host, and as hinge
For Türkiye the summit was a debut on the alliance's biggest stage, and the host played it as an arrival. "NATO has gained new perspective and acceleration with the Istanbul summit," then Prime Minister Recep Tayyip Erdoğan said as it closed, according to Cihan. Anadolu Agency reported that NATO's senior officials left the summit "extremely pleased" with the result.
The logic of holding it in Istanbul was geographic. Türkiye sat at the seam between the Europe NATO defended and the Middle East and Afghanistan its new missions reached into, the member whose map made the out-of-area decade legible. That is the role Türkiye brought to the table in 2004: position.
The summit week was more than communiqués. US President George W. Bush attended, security was heavy, and the summit drew protests, Greenpeace activists staged a demonstration around the event, and the run-up was tense enough that a blast struck Ankara ahead of Bush's visit. The alliance met behind a cordon, as it will again in Ankara.
The thread to 2026
The clearest line from Istanbul to Ankara runs through the Gulf. The Istanbul Cooperation Initiative launched in 2004 is still NATO's framework for its Gulf partners, and those partners, Bahrain, Kuwait, Qatar and the UAE, are on the agenda again at the 2026 Ankara summit. What Türkiye's first summit started, its second one is still working through.
What changed is Türkiye's place in the picture. In 2004 the country mattered to NATO for where it sat. By 2026, as the alliance swings back toward hard collective defense in the phase now branded NATO 3.0, Türkiye arrives with the second-largest army in the alliance and a defense industry selling to its allies. Now it matters for what it builds. The distance between those two summits, both hosted in Türkiye, is the distance the country has traveled inside NATO.
The alliance that met in Istanbul had 26 members and a decade of expeditionary missions ahead of it. The one meeting in Ankara has 32 and is turning back toward defending its own ground. Both summits are Turkish milestones. What they measure, held 22 years apart in the same country, is how much both NATO and its host have changed.