Nuclear could really clean up the shipping industry and provide numerous other benefits.
That or always make it so valuable to always strip the power unit to use again.
How proliferation of fissionable U-233 is different from proliferation of fissionable Pu-239? Both share ability to be separated from fuel without enrichment factories, both can be used to build a bomb.
I like thorium cycle, but proliferation should not be used as argument for it.