Dr Scott Marmion (Letters, September 21) asks why we should care about international law. We should care because it’s the civilized way to enable different countries to deal with each other.

By proposing to break international law Boris Johnson shows that the UK government can no longer be trusted to keep its word. As well as being unethical it does not make good business sense. Who would make a deal with someone who breaks their promises whenever it suits them?

It’s not really surprising given the number of promises Johnson has already broken. The Leave campaign promised there was no question of a No Deal, or leaving the Single Market and Customs Union, that an ‘oven ready deal’ better than EU membership would be the ‘easiest thing in the world’. Oh, and there was going to be all that money for the NHS. Instead, leaving the EU has now cost the UK as much as we paid during our 40 years membership, with none of the benefits.

It would be great if all those promises materialize on January 1.

But given Johnson’s disregard for international law, I’m not overly hopeful.

M. Kendall, Wheldrake, York