WASHINGTON (AP) — Giving himself credit for tough diplomacy, President Donald Trump is describing a burst of activity by Mexican authorities to keep Central American migrants from getting to the U.S. border.

That's an apparent mirage as Trump retreats from his latest threat to seal off the U.S. from Mexico.

Trump was wrong when he said last week that Mexico was doing "NOTHING" about migrants coming north. It markedly tightened migration controls during the Obama administration and detained over 30,000 foreigners in the first three months of this year.

And it's not evident now that Mexico has s...