The pressure caused by the Iran war on the American military caused Trump to withdraw from the ground attack on Yemen

According to the New York Times:

🔹Trump decided not to carry out airstrikes against Yemen, and then he gave up on this decision because the Pentagon made the preparations for the operation.

Most members of Trump's inner circle had serious doubts about the US entering the Saudi war with Yemen or were against it; especially given the pressures the war with Iran is currently putting on the US military.