As much as any other world leader, Claudia Sheinbaum has gained the reputation of a Trump whisperer.

Over and over, the Mexican president has entered tense negotiations with President Trump and — to the surprise of many — exited with praise.

“I like her very much,” Mr. Trump said in the Oval Office in February. “I did this as an accommodation, and out of respect for, President Sheinbaum,” he said after pausing tariffs against Mexico in March.

But the honeymoon seems to be ending.

Over the past several months, Mr. Trump has amped up his intense pressure campaign on Mexico with a multipronged offensive that has squeezed Ms. Sheinbaum, put her on the defensive and left her with few good options to react.

The United States has deployed nearly 10,000 troops at the Mexican border; accused Mexican banks of money laundering; threatened layers of devastating tariffs; revoked the visas of certain Mexican politicians; and declared several Mexican drug cartels terrorist organizations.

At each step, Ms. Sheinbaum has grit her teeth and stressed that there was a red line Mr. Trump must not cross: infringing on Mexico’s sovereignty, particularly with unilateral military action.

Then, news broke this month that Mr. Trump had secretly directed the Pentagon to explore military action against cartels.