Overview
- Ukraine launched enhanced, multi-agency counter‑intelligence and counter‑sabotage operations on Thursday, May 21, concentrating resources in five northern oblasts that border Belarus and Russia.
- The Security Service (SBU) coordinated the operation through its Anti‑Terrorist Centre with the National Police, Armed Forces, National Guard and Border Guard carrying out identity checks, vehicle inspections and territory searches.
- Ukrainian officials say the steps were prompted by Belarusian and Russian statements that tactical nuclear munitions were moved to field sites and that large joint exercises involving tens of thousands of troops were under way.
- The actions were ordered by the Supreme Commander‑in‑Chief's staff under President Volodymyr Zelensky and are framed as lawful, preventive measures to stop infiltration, sabotage and intelligence activity; civilians were urged to carry ID and follow curfew rules.
- NATO and Ukraine warn the reported nuclear-capable deployments raise the risk of escalation and could prompt stronger diplomatic and military responses while disrupting daily life in border communities.