On Day Zero, it doesn't take much at all... underwriters get spooked, ships drop anchor.

But the system will adapt, one way or another, if this drags out. They're already talking about it in the biz media...

https://europeanbusinessmagazine.com...-critical-oil/

It doesn't take much to spook insurers who are risk averse, and also averse to hard-to-quantify risk.

It takes a lot more to actually physically interdict a relevant % of shipping... we did it to the IR Navy, but of course we have multiple CSG's, surface combatants, subs, and numerous land-based tacair in theater.