Russia exports lots of oil from the Baltic Sea in ships that go through the narrow passages around Denmark. These ships are badly maintained, and likely to cause disaster even without an intention to do so.

Whether the ships are insured is almost irrelevant, since an insurance company could hardly make up for the damage that a big oil spill could do in those confided waters. The crucial issue is to stop allowing unseaworth ships to pass through.

Regardless of future between Ukraine and Russia, it would be wise to require all oil shipments between the North Sea and the Baltic Sea to be sent through pipelines across Denmark, not by ship. Pipeline leaks on land will make smaller spills than ship disasters.