President Trump on Friday announced a trade deal with China that he called “tremendous” or “tremendously” positive 15 times. The details look far more modest to us, but this truce in the trade war beats the alternative of escalating tariffs that have already caused a significant global economic slowdown.

Mr. Trump said China will make some $40 billion to $50 billion more in agricultural purchases over two years and has promised to better protect intellectual property and welcome more foreign financial services. In return the...