> wonder if uninvolved nations will also be required to pay the safe passage fees

If Iran is smart (and Iran gets the fees, which remains a big if) they would exempt Spain.

Not really practical to exempt Spain even if they wanted to, with Spain being within the EU and therefore able to freely move goods and services to other EU nations.

> with Spain being within the EU and therefore able to freely move goods and services to other EU nations

Fair enough. Spain gets N free tankers a month, with N calibrated to Spanish consumption.

Aside from Iranian allies, it seems likely.

So this would have the downstream effect of further degrading international sentiment towards US military operations in the future.