I just found that your overseas provinces could be blockaded so they'll produce no income at all. You cannot starve enemy troops but nevertheless would hurt their economy a bit. (And probably your own economy, imagine UK suddenly can't sell her grain/tea/whatever produced in India...)
so, in case of a war with UK next time, send your ships to block off all of the Indian coast if you don't have spare troops to capture it atm...
so, in case of a war with UK next time, send your ships to block off all of the Indian coast if you don't have spare troops to capture it atm...