The furor over President Trump’s attempt to extort Ukrainian President Zelenskiy over military aid raises an obvious question: Why should the United States care so much about Ukraine? Steven Pifer writes that a big part of the reason is the Budapest Memorandum, signed 25 years ago this week.

On roughly 75% of land in most U.S. cities, it is illegal to build anything except single-family detached houses. Using Washington, D.C. as a case study, Alex Baca, Patrick McAnaney, and Jenny Schuetz show how zoning rules can be relaxed to build more homes, improving affordability and economic opportunity for residents.

“As more time passes, I find it decreasingly likely that Trump will fundamentally transform the United States in terms of immigration, foreign policy, or the nation’s relationship with Islam and Muslims.” As a part of the Muslims in the West series, George Hawley takes at a look at the relationship between populism and Islam in the United States.