Western intelligence agencies possessed detailed knowledge of Vladimir Putin's plans to invade Ukraine months before the February 2022 assault, but their warnings were dismissed by political leaders and military analysts who considered a full-scale invasion implausible, according to a major investigation published Thursday by The Guardian.The revelations expose a critical intelligence failure—not in gathering information, but in the inability to convince decision-makers to act on accurate assessments. To understand today's headlines, we must look at yesterday's decisions: the West's response to Russia's 2014 annexation of Crimea had been relatively muted, creating a false sense that Putin would stop short of all-out war.Both the CIA and Britain's MI6 obtained copies of Russian military planning documents through human intelligence sources in Moscow, the Guardian investigation reveals. These documents detailed troop movements, supply logistics, and invasion routes—intelligence that proved remarkably accurate when the war began.Senior intelligence officials in Washington and London presented their findings to political leaders in late 2021 and early 2022. President Joe Biden took the warnings seriously enough to publicly predict an invasion, but European allies remained skeptical, with some suggesting American intelligence was exaggerated."The intelligence was about as solid as it gets," a former senior NATO official told The Guardian. "But there was a widespread belief that Putin was bluffing, that he would use the threat of invasion to extract concessions, not actually go through with it."German and French officials, pursuing diplomatic engagement with Russia until days before the invasion, questioned whether the intelligence accurately reflected Putin's intentions. That skepticism delayed Western preparations and may have encouraged the Russian leader to believe the West would not mount a unified response.The investigation draws on interviews with more than 50 current and former intelligence officials across five countries, along with declassified documents. It reveals that some intelligence agencies even obtained the specific date Russia would launch its assault—information that was shared with Ukrainian officials who used it to evacuate government functions from Kyiv.The failure to act decisively on the intelligence carries lessons that extend beyond Ukraine. As Western agencies monitor Chinese intentions toward Taiwan and Russian designs on NATO members, the ability to translate intelligence into preventive action becomes crucial.Four years into the war, Ukraine has suffered tens of thousands of casualties, millions have been displaced, and European security has been fundamentally reshaped. Whether earlier and more forceful warnings could have deterred the invasion remains a haunting question for those who possessed the intelligence but could not convince others of its significance.