Next week’s debate, in Des Moines, was likely going to focus on health care and other domestic issues, but the agenda will probably be dominated by the Trump Administration’s killing of Iran’s General Qassem Suleimani and America’s history of war in the Middle East. The New Yorker’s Eric Lach, who is in Iowa, describes how the candidates are honing their positions. Plus, the contributor Anna Wiener reflects on the changing face of Silicon Valley; and the Moscow correspondent Joshua Yaffa describes how to succeed in Putin’s Russia.