That's true, but Mexico also exports huge quantities of narcotics to Canada, Europe, and other countries. Who is responsible for solving the problem?

And regardless of responsibility for causing or solving the problem, we absolutely need to improve border security. Physical fences aren't very effective in most areas but better sensors and more human guards could do a lot to reduce smuggling and human trafficking.

And has spent billions attempting to limit their purchase & international movement. Maybe it should continue to be a joint effort rather than finger pointing that one side isn't doing enough.

which means the US can dictate Mexican policy?