UK Prime Minister Theresa May has warned the West must keep up its pressure on Moscow over its assault on the Syrian city of Aleppo as a flotilla of Russian warships sailed up the English Channel, thought to be heading towards the Syrian coast.
The flotilla left northern Russia on Saturday. Since then it has steamed around Scandinavia, down the North Sea and is now passing through the Channel towards the Mediterranean.
Defence officials said UK Royal Navy ships would flank the task force "every step of the way".
Just after first light on Friday morning in the Channel, the usually friendly waters were tense. An echo of the Cold War was playing out, and UK and Russian battleships eyeballed each other across the seas.
The most menacing was Russia's only aircraft carrier, the Admiral Kuznetsov, which was seen launching a jet into the skies off the coast of Norway just two days ago. Since then, a flotilla of eight ships has stalked south from the North Sea en route to Syria, and at around 11am on Friday an ominous plume of black smoke could be seen for miles in the distance.
The Admiral Kuznetsov is vast. It's like a block of flats floating past the White Cliffs of Dover. At least four or five other Russian war ships have also been spotted, so if part of all this is show of strength, it's doing the trick.
But the English Channel is one of the busiest waterways in the world, and ultimately the Russians are doing nothing wrong by sailing along the international seas. It isn't the first time they have sailed there either; a fleet did the same two years ago, and back in April.
They were without an aircraft carrier though, and defence analysts say this week is all about Mother Russia flexing her muscles and being deliberately provocative. After all, it isn't the only path the taskforce could have taken.
For the UK it is a few days of heightened diplomatic tension, albeit at a time when relations with Russia are strained to say the least.
But the armada is heading to Syria, and while the rest of the world is just getting a look at Russian military might, the people of Syria will be feeling it first-hand.
The fleet is not new. The Admiral Kuznetsov has been beset by breakdowns, and yet none of that matters to the bombs that drop from the jets they carry.
The UK Ministry of Defence says British boats will man-to-man mark the ships while they're in its waters. It's when they're unchallenged off the Syrian coast that their real mission begins.