Newsweek has contacted the Russian Foreign Ministry for comment.

NATO's chief said on Monday that there is a "lone and broken Russian submarine limping home from patrol" in the Mediterranean Sea.

VChK-OGPU, a Telegram channel that publishes purported Russian security leaks, reported on 27 September that fuel was leaking into the hold of the Novorossiysk in the Strait of ­Gibraltar, raising the risk of an explosion.

The submarine’s crew were carrying out a “routine inter-fleet transfer” in the Mediterranean Sea, the Russian navy said in a statement carried by Russian state news agency Tass on Monday. The navy said that under international law, submarines must break the surface when traveling through the English Channel.

Intrusions into NATO’s airspace blamed on Russia have reached an unprecedented scale, raising questions about whether the Kremlin is trying to test the alliance’s willingness to respond to a direct attack or divert its attention and resources from the war in Ukraine.

A new Danish intelligence assessment blames Russia for employing various 'gray zone' tactics against its forces.

Those recent incursions, including drones into Poland and armed MiG fighter jets into Estonia, have spurred discussions over new steps Nato militaries can take to better deter Russia, including more aggressive responses and deploying more lethal assets on its borders.

Vaindloo island, a tiny rocky outcrop in the Gulf of Finland, is serving as an unlikely barometer for rising tensions between NATO and Russia.

Nato is discussing new rules that could make it easier to shoot down Russian fighter jets. The talks are focused on drawing up a single set of guidelines for engaging enemy aircraft. Defence chiefs want Russian jets carrying ground-attack missiles over allied airspace to be possible targets.

Russian incursions into NATO airspace are fueling divisions among allies, with some warning that repeated Article 4 signals risk weakening deterrence without real action.

A senior Estonian military official said Russian pilots ignored signals from Italian jets during a 12-minute violation of Estonian airspace.

The Trump administration expects Europe, not the US, to lead the North Atlantic Treaty Organisation (Nato), defence secretary Pete Hegseth said, marking an apparent shift in Washington’s stance toward the 76-year transatlantic alliance.