Recent U.S. intelligence assessments indicate Russian President Vladimir Putin could try to test NATO’s resolve by launching a limited attack on an allied country within the next few years, according to three sources familiar with those reports. The intelligence assessments outline several possible scenarios for Russian escalation, ranging from a cyberattack to a small-scale incursion intended to challenge NATO’s unity and commitment to Article 5, which states that an attack on one member is an attack on all, without necessarily crossing the threshold for an allied response, the sources said. While how and when Putin might do so remains an open question, one of the sources said he is most likely to escalate in some way by targeting the Baltics or Poland. The Wall Street Journal first reported on the recent assessments. U.S. and NATO officials believe Putin may choose to escalate against NATO if he is unable to secure a face-saving off-ramp to the war with Ukraine, the sources added, noting the Russian president’s window for choosing his next course of action spans between now and the next few years. Martin O’Donnell, a senior NATO military spokesperson, declined to comment on classified intelligence assessments but said NATO is “always thinking through and preparing for any number of scenarios.” “NATO is watching and we are ready to deter and defend as necessary, which we continue to demonstrate,” he added. There have been numerous instances over the last few years of Russia encroaching on NATO territory. In May, a drone carrying explosives hit an apartment building in Romania as Russian forces attacked a nearby Ukrainian port, injuring two people. And last September, NATO fighter jets shot down multiple Russian drones that had violated Polish airspace during an attack on Ukraine. And just this week, the U.S. assessed that an explosive-laden drone discovered at an airport in Germany overnight on Wednesday belonged to a Russian intelligence service, a U.S. defence official in Europe told CNN. The official said the drone was carrying military-grade explosives; CNN previously reported it was discovered by an airport staff member in a secure area of cargo flight operations. CNN asked the Kremlin for comment on the U.S. intel assessment on Putin as well as the assessment on the drone. “Drone sightings, drone threats including in a hybrid context, are something we know from the past,” German Interior Minister Alexander Dobrindt told reporters on Wednesday. “That a drone armed with explosives is at an airport is a new threat scenario.” Dobrindt indicated Thursday that the drone could be tied to “foreign powers” though he stopped short of providing specifics. The German National Security Council, led by Chancellor Friedrich Merz, met on Friday to discuss the airport incident. The intelligence assessments on Russia’s plans also come amid heightened concerns over the U.S.’ munitions stockpile which has been significantly depleted in the war against Iran, and an increase in civilian casualties from Russian long-range weapons. CNN previously reported that nearly 80 per cent of its THAAD missile interceptors — a key missile defence system — have been exhausted in the war compared to pre-war levels, as well as roughly half of its Patriot interceptors. Meanwhile, the UN has said that civilian casualties from Russian long-range weapons increased 60 per cent between January to June, compared to the same period last year. In one night of attacks this week, Russian ballistic and anti-ship missiles killed at least 17 people and wounded dozens more. None of the missiles were intercepted by Ukrainian defences, CNN reported. Concerns over key munitions and interceptors are impacting the way senior military commanders are planning for potential future conflict, including escalation against NATO by Putin or war with China in the Pacific. U.S. President Donald Trump has privately complained in recent days about reports of the U.S.’ dwindling stockpiles due to the war with Iran, including last week at a Cabinet meeting at Camp David, six sources familiar with the meeting previously told CNN. “The U.S. has massive amounts of ‘munitions,’ especially of certain types,” Trump said on Truth Social late Thursday night. “Additionally, large amounts are being manufactured and shipped to the U.S. as needed. Defence companies are building the largest number of plants and factories in our country’s history.” The recent intelligence assessments also come as U.S.-led diplomatic efforts to bring the war between Russia and Ukraine to an end have stalled. Ongoing U.S. and European sanctions against Moscow have had an impact on Russia’s economy but have not stopped Putin’s continued assault on Ukraine.