This is a game changer:

In the early morning hours, Ukrainian forces carried out an amphibious landing on the Tarkhankut peninsula of Crimea where they destroyed a Russian S-400 air defence system.

Knowing the difference Patriot air defence systems have made for Ukraine, taking out the corresponding S-400 systems in Crimea can spell serious trouble.

Especially now, where some of these systems have been pulled back to protect Moscow and airfields inside Russia against Ukrainian drone attacks.