NATO Burden-Sharing and the 5% Spending Push

What it is

Burden-sharing is NATO's framework for distributing the costs of collective defence across its 32 member states. Allies contribute through their own national defence budgets, tracked as a share of GDP. The commitment is political, not treaty-bound; missing the target carries diplomatic cost, not legal penalty.

The "5% push" refers to the Hague Summit agreement of June 2025, where 31 of 32 members committed to raising annual defence spending to 5% of GDP by 2035. The target has two tiers: at least 3.5% for core military expenditure covering personnel, equipment, and operations; and up to 1.5% for broader security spending such as cyber defence, critical infrastructure protection, and defence-industrial investment. The tiered structure was designed to bridge traditional military budgets with modern, sub-conflict security demands.

History

NATO's first spending benchmark came at the 2014 Wales Summit: halt defence budget declines and move toward 2% of GDP within a decade. Russia's annexation of Crimea was the catalyst. Most European members ignored the Wales target for years, hovering below 1.5%. By 2025, European and Canadian spending had climbed to a collective 2.3% of GDP, and for the first time all 32 members met or exceeded 2%.

US President Donald Trump pressed for 5% at the 2025 Hague Summit, echoing his domestic pledge during the 2024 campaign. European leaders agreed to the tiered structure partly as a face-saving formula, partly in response to the Iran war, in which the United States bore the bulk of a campaign that depended heavily on European basing. Over 4,000 US aircraft operated from European bases during the campaign.

Current state

As of July 2026, only Poland (4.3% of GDP) approaches the 3.5% core target. The Baltic states are close; most NATO members are drafting multi-year roadmaps. Spain holds a formal exemption, the only member to refuse the 5% pledge. The E5 group (Germany, France, the UK, Italy, and Poland) met in Berlin on June 23-25 and reaffirmed 5% as their collective line, pointedly excluding Madrid from that meeting.

The UK Defence Investment Plan published June 30 committed £298 billion over four years, targeting 2.7% of GDP by 2028 and 3.5% by 2035. The spending commitment outlasted the government that made it: Defence Secretary John Healey and Armed Forces Minister Al Carns resigned on June 11 over the pace of the increase, triggering the collapse covered in 国防費をめぐる反乱、ヒーリーとカーンズが辞任しスターマーの失脚を加速. SIPRI projects that reaching the 5% target across all NATO members by 2035 would require aggregate annual spending of US$4.2 trillion, up from today's US$1.4 trillion.

Relationships

The burden-sharing debate directly shapes the July 7-8 Ankara summit, where national roadmaps and Ukraine aid commitments are both on the table. The Berlin E5 session aligned Europe's five largest defence spenders before Ankara. Italy, despite endorsing 5% in Berlin, blocked NATO declaration language on Ukraine aid per イタリア、2027年のウクライナ支援を2026年水準に維持するNATO草案文言を阻止, exposing the gap between spending pledges and operational commitments. National debt levels complicate the arithmetic: France's public debt stood at 112% of GDP in 2024 and Italy's at 135%, constraining how much each can borrow to fund rearmament.

What to watch

• Whether the Ankara summit sets mandatory milestones for the 5% path or leaves implementation voluntary and self-reported.
• Spain's standing in NATO decision-making as its exemption persists into future summit cycles.
• The 2029 review point, when NATO will formally assess whether the 3.5% core target is on track.
• Whether defence-sector inflation and industrial absorption limits reduce what the additional US$2.7 trillion in annual NATO spending can actually deliver in fielded capabilities.