I wouldn't be averse to depth charging a fiber optic cable (more specifically - damaging their ability to operate the great firewall) so long as there are no human casualties. Even better if it could be done without disrupting Chinese Internet.
Unfortunately, most people's response would be "What's a GitHub"?
If China was loading missiles into cargo ships that fire at northern california, we wouldn't continue to let ships enter/leave China. As to the debt that China owns, they're already in a position of playing games with currency and resources to assert a dominant position.
Eventually you have to stand up for yourself. As to the do-dad manufacture costs, well I think we'd be okay if we had to go a couple years without any new do-dads.