US intelligence warns Putin may test NATO with limited attack between autumn 2026 and 2029

US intelligence revises assessment

US intelligence has revised its earlier assessment that Vladimir Putin would avoid provoking NATO while Russia remains militarily engaged in Ukraine. According to American officials cited by the Wall Street Journal, the assessment changed in early 2026. Putin is under growing pressure from the lack of a breakthrough on the front and from Ukrainian long-range drone strikes targeting Russia's fuel industry and, most recently, the e-commerce conglomerate Wildberries. Russian forces are suffering significant losses and achieving only limited progress, while the pace of their offensive has slowed. US officials fear Putin could become more dangerous if cornered and may resort to what one article described as a "plan B" based on the principle of "flight forward."

Scenarios under consideration

The intelligence analyses outline several potential forms of Russian action against a NATO member state. These range from a cyberattack to the deployment of unmarked armed groups to occupy a fragment of territory, up to a limited land incursion on the alliance's eastern flank. According to the assessments, possible Russian actions could occur between autumn 2026 and 2029. The probability of the most extreme scenario, a limited land incursion, is currently assessed as low but growing over time. Such a step would trigger Article 5 of the North Atlantic Treaty, which commits member states to collective defence. However, Article 5 does not clearly define the NATO response to cyberattacks or hybrid threats, making sub-threshold actions more likely and potentially more divisive within the alliance.

Russia's strategic goal

US and European officials increasingly see signs that Russia is conducting probing actions to test NATO's resolve. The WSJ cited a Russian missile falling on Polish territory and drones violating Romanian airspace among such incidents. If Putin decided to attack NATO during the ongoing war in Ukraine, his goal would be to drive a wedge in the alliance, US officials believe. Experts emphasise that the Kremlin's strategic goal remains undermining NATO's credibility and weakening the bond between the United States and its European allies.

The question is how the United States would respond in such a case. One of Russia's goals has always been to undermine NATO's credibility and separate the United States from its allies.

NATO and Swedish warnings

NATO spokesperson Colonel Martin O'Donnell said the alliance is monitoring the situation and is prepared to deter and defend if necessary. Separately, Sweden's supreme commander of the armed forces, General Michael Claesson, warned in Svenska Dagbladet about the risk of sabotage, which he said is "completely obvious for all states supporting Ukraine." Claesson did not rule out military operations, including those involving special forces.

US ammunition concerns

The new intelligence assessments coincide with US officials' concerns about shortages of critical ammunition types and air defence systems. According to a CSIS report, the US Army currently has fewer than 1,000 Patriot interceptor missiles and fewer than 250 THAAD interceptor missiles. A Reuters source said the US has used slightly less than half of its Tomahawk cruise missile stockpiles since the start of the war with Iran, and "nearly all" ATACMS and PrSM missiles. The WSJ notes that the depleted categories include precision-guided long-range missiles, tactical missile systems used by ground forces, and short-range Stinger surface-to-air missiles. Donald Trump denied these concerns, stating the US is in a "very good situation" regarding weaponry.