Russia is preparing a limited, deniable attack on NATO territory designed to break the alliance's collective-defense promise rather than start a full war, and European leaders now openly expect it within months — bad news for NATO's eastern flank and for Ukraine's long-term support.

• Russia cannot beat NATO as a whole, but it can beat individual members one at a time if Article 5 (the "attack on one is an attack on all" rule) stops being trusted.
• The likely tactic is a small, hard-to-answer move: "stray" missiles or drones hitting a NATO country, a few hundred troops seizing empty forest or an island, or a Crimea-style grab of a Russian-speaking border city like Narva in Estonia.
• The trap is political, not military: NATO either sacrifices soldiers over worthless land, or refuses and proves the alliance guarantee is hollow, letting Russia keep pushing.
• Russia is betting the West won't accept casualties, pointing to the political fallout in Washington over a few dozen US deaths in the Iran conflict and Europe's refusal to send ships to the Strait of Hormuz.
• US and European intelligence say an incursion could come as early as this month; Poland's Tusk, France's Macron, and Germany's Merz all warned last week of "decisive months," while Lithuania plans evacuations of Vilnius and Germany models wartime hospital capacity.

Outlook: Expect a Russian provocation on NATO's eastern edge in the coming months, with the alliance's survival hinging on whether the US and Europe show up when a small member calls for help.