BELGIUM-ATTACKS — Islamic extremists strike in the heart of Europe, killing at least 31 people and wounding scores of others in back-to-back bombings of the Brussels airport and subway that again lays bare the continent's vulnerability to suicide squads. 

EUROPE'S NEW NORMAL — Paris, Copenhagen, Brussels. In just over a year three European capitals have been ravaged by bombs and gunfire. After each attack life returns to normal. But it's a new normal for Europe, where terror alerts are always on high and people in cities so far spared major violence assume it's a matter of when, not if. 

OBAMA-CUBA — Capping a remarkable visit to Cuba, President Barack Obama declares an end to the "last remnant of the Cold War in the Americas" and urges Cuban citizens to pursue greater political freedom. 

PRESIDENTIAL RACE — Under a shadow of overseas violence, Donald Trump and Hillary Clinton pad their leads with victories in Arizona as the 2016 presidential contest turned into a clash over who could best deal with Islamic extremism.

KERRY-RUSSIA — Secretary of State John Kerry heads to Moscow for talks on Ukraine and Syria as the attacks in Brussels underscore the urgency of fighting the Islamic State group. By Diplomatic Writer Matthew Lee. 

BRAZIL-CORRUPTION — A Brazilian Supreme Court justice rejects a motion that would have let former Brazilian President Luiz Inacio Lula da Silva take a Cabinet post. 

RUSSIA-UKRAINIAN PILOT — A Russian court sentences a Ukrainian pilot to 22 years in prison after convicting her for complicity to murder in the 2014 deaths of two Russian journalists in eastern Ukraine, opening a door to a possible prisoner swap between the two countries.