[HWR_14]

Military ships are also allowed "innocent passage". There are a lot of things they aren't allowed to do while on such a passage (e.g. launch planes, leave on certain radars, do weapons drills), and have to go as quickly as possible. Some countries (Romania, Lithuania) have declared that the mere presence of nuclear weapons on ships violates innocent passage in their eyes, and in general adding nuclear propulsion creates more paperwork.

It doesn't matter if that's the case though. The British were explicitly conducting gunnery drills violating a condition of innocent passage. They did it to violate innocent passage. Because the point was to assert that Crimea (and it's surrounding territorial waters) do not belong to Russia and therefore they can do what they want (subject to Ukraine's approval). This is similar to what US warships do near the fake islands built by China in the South China Sea. Constantly objecting prevents annexations from becoming fiat accompli.

The downside is there are often missile locks between the armed forces of two countries, and, since firing on a warship is casus belli, may cause a war between nuclear powers.