[atoav]

> Isn't "sinking the Russian Black Sea fleet" directly striking Russia?

Under certain viewpoints it is the difference between attacking the US command in Iraq and striking troups in New York.

The black fleet is stationed on annexed land as of the view of most UN member states. An attack on troups stationed on foreign soil is not the same as an attack on troups stationed e.g. in the capital of an country. The black fleet are military targets on the soil/waters of an invaded country in an attack war. This is the status most foreign ministries would tell you the black fleet has currently.

The question now is: What are the consequences of doing nothing, should Russia deploy tactical nukes?

Most analysts would say there are bigger consequences to doing nothing than to doing something of limited scale unless your goal is normalizing nuke deployment (very bad idea).

So where would you retaliate instead?

[mrjin]

Were you seriously talking about laws? For those super powers, they are the law as long as they can win the war.

[atoav]

Yes and no. These superpowers are playing their power games on a world stage. As such they sometimes need the crowd on their side in order to win. That means that thin veneer of law does indeed count. After all each nation tries to keep their population under the believe that they are indeed the good ones.

That means war cannot move unrestricted from the rules that govern it. Or let's say it can, but at a (often significant) cost.