The Kremlin is increasingly testing the boundaries of Europe's response to Russian hybrid warfare, with leaders warning that Moscow may be preparing to act more aggressively against NATO allies. According to officials, Russian President Vladimir Putin might be considering ways to challenge NATO's commitment to defend its eastern flank or react to actions that fall short of full-scale war. This comes at a time when the U.S. is dealing with other global conflicts and has been considering reducing its military presence in Europe. A report from Denmark’s Defence Intelligence Service suggested that Russia is likely to increase its hybrid warfare efforts, which involve non-traditional methods of conflict such as cyberattacks, disinformation, and limited military actions, in the coming months. The report also noted a low but rising risk that Russia might conduct a limited military strike against one or more NATO countries that share a border with Russia. A notable incident occurred when a Russian drone carrying explosives was discovered at an airport in eastern Germany near a Ukrainian aircraft last month. Berlin blamed Russia for what it described as a failed attack and imposed a diplomatic freeze, though Moscow denied any involvement. This event, along with a series of other incidents—such as attacks on defense facilities in Estonia, rail networks in Poland, and the power grid in Germany—has raised concerns about Russia's growing threat in Europe. These incidents have often lacked clear attribution, leading to increased speculation. Drone incursions into European airspace have become nearly routine, creating anxiety in border towns near Russia. In Ukraine, a passenger train was struck less than two miles from the Polish border earlier this month, an event that occurred as European diplomats were returning from Kyiv on the same rail line. Another train, carrying former CIA Director David Petraeus, was at the station when the drone attack happened. Just days later, NATO fighter jets intercepted and shot down a drone in the airspace of Lithuania, one of the Baltic states that are particularly close to Russia and could be potential targets for future attacks. Polish Prime Minister Donald Tusk suggested that these incidents are part of a broader strategy by the Kremlin to conduct drone and missile attacks in Europe, aiming to weaken any unified response from NATO. Russia has denied involvement in any of these incidents and has consistently rejected accusations of conducting hybrid warfare or sabotage in NATO countries. Earlier this month, Russian President Vladimir Putin accused European leaders of trying to provoke a war against Russia and of frightening their populations with an imagined threat. A Russian state news agency, RIA, briefly published an op-ed outlining a potential scenario for a "lightning fast" war that Russia might launch against a NATO state, specifically targeting the Baltic nations. However, the article was quickly removed, with RIA stating it did not align with editorial policy or Russia's state policy. U.S. allies believe the pattern of incidents reflects Russia pushing the limits of what is acceptable in Europe. "With these incidents now so frequent and so brazen, it is increasingly difficult to distinguish them from actual acts of war," said Katja Bego of Chatham House. The risk of more serious escalation, even if unintended, is growing. The Baltic states have taken precautionary measures, with Lithuania planning to evacuate older adults and lifting its ban on hosting nuclear weapons. Finland has advised citizens to be mentally prepared for new sabotage attacks, while France is developing a plan to protect its critical infrastructure. The looming question is how NATO will respond, especially with Article 5—its collective defense clause—potentially at stake. For Moscow, these actions could highlight divisions among Western allies and challenge the unity of the NATO alliance at a time when U.S. commitment to European security is being questioned.