The US has closed all pedestrian and vehicular traffic at the San Ysidro main border crossing just south of San Diego, after several hundreds of illegals tried to rush through Mexican riot police and tear gas to attempt entry to the US.
Step Two should be closing the entire border for a week, and telling Mexico to round them up and return them to their southern border, or the closure will be indefinite. And impound all remittances to Mexico to cover the cost of the military presence there. The minimum tariff should start at 40% on them, and escalate at 10% per week.
StepThree: weapons free, and no bag limit.
And if the military is too squeamish to do that, it's going to start happening free-lance.
I'm betting even closing the border for a day would topple the Mexican government if they failed to intervene and do their effing jobs, because it would cripple their economy, while leaving ours virtually unscathed.