Gen. Joseph Dunford becomes U.S. commander in Afghanistan

Outgoing Gen. John R. Allen speaks of progress made during his tenure. ‘This is what winning looks like,’ Allen says. Dunford stresses continuity.

KABUL, Afghanistan — Gen. Joseph F. Dunford Jr. took over Sunday as the newest and probably last U.S. commander in Afghanistan, charged with ending America’s longest war even as insurgents continue to challenge the U.S.-backed Afghan government.