We've considered that the Uranium one deal shipped uranium to Russia but either diverted some of it or sent some from the same batch to secret labs in Iran/N Syria.

The final goal being to set off a nuke that could be traced back to the Russians and make that the basis for a war that would make the Germany/Russia pipeline make sense.

What if this was that weapon?

You wouldn't need a lot of uranium for a small tactical weapon and if you built it on board the tug, it could be a lot larger and cruder.

You wouldn't need as much time to miniaturize and shield the bomb. you could just shield the boat or the lower hull.

The narrative would be simple.

"Russia destroys bridge in attempt to seal off Ukraine"

Once that was established, the nuke could be revealed.

After that, war would be very difficult to avoid, particularly if you add some aggravating factors like an airliner shoot down and the other standard FFs

Maybe the clockfags can make a connection.

There are 7 Sum of all fears crumbs