While there, Mr. Trump signed an agreement to send an additional 1,000 American troops to Poland as a hedge against Russian adventurism in the eastern stretches of Europe, bolstering about 4,500 already there on a rotating basis. He did not agree to the permanent presence Poland has sought. (Its leaders even suggested naming a base Fort Trump.)

History: After Russia’s incursion into Ukraine and annexation of Crimea in 2014, the U.S. and NATO allies began sending small units of troops to Poland and the Baltic states on a rotating basis. It was intended as a deterrent to any further moves by Moscow, a reminder that those nations were now under the protection of the North Atlantic alliance’s all-for-one defense umbrella.

Related: This morning, “The Daily” takes you to Poland, where a nationalist government has been in power for years. Begin listening in a few hours, or check out previous episodes in this week’s five-part series on the rise of nationalism and populism in Europe.

Britain to cut net greenhouse gas emissions to zero

Prime Minister Theresa May proposed legislation stating that the country bring its net production of greenhouse gases to zero by 2050.