US defence officials raised the security alert level at military bases in Europe over the weekend in response to vague threats from the Kremlin over Ukraine’s use of long-range weapons on Russian territory, according to US and western officials.

Officials said no intelligence about possible Russian attacks on US bases had been collected. Any such attack by Russia, whether overt or covert, would be a significant escalation of its war in Ukraine.

Russia has been stepping up acts of sabotage in Europe, hoping to disrupt the flow of materiel to Ukraine. So far, no US bases have been targeted in those attacks, but US officials said raising the alert level would help ensure service members remain vigilant.

Throughout the war, US officials have assessed that President Vladimir Putin is loathe to expand the war beyond Ukraine’s borders.

But stepped-up US and European aid — and the easing of restrictions on how that materiel is used — has caused consternation in Moscow, according to US officials. Russia’s recent statements have made some US and European officials wary.

Ukraine has been using longer-range US missiles known as ATACMS to strike deep into occupied Crimea. The US has also said Ukraine can use them in cross-border attacks on Russian military targets.

New York Times News Service