How Russia might answer a Danish Straits closure

What might Russia do if Denmark and Sweden closed the Danish Straits to Russian shipping?

It could contest the closure, but indirect pressure on other NATO states and economic retaliation may be more practical than coercing Denmark or Sweden directly.

Russia would probably protest and might attempt to force passage with warships. Denmark could argue that passage was no longer innocent if the ships intended violence, a concept with First World War precedents in the straits. Direct retaliation against Denmark or Sweden offers Russia limited leverage. Pressure against Finland or the Baltic states, broader trouble for NATO, and economic retaliation are presented as more plausible alternatives.