In late 2009, President Barack Obama announced a surge of troops in Afghanistan. In the first full year of that operation, 2010, of the nearly 500 U.S. troop deaths in Afghanistan, more than half were from Helmand province. It was the deadliest year of the war for American troops and also the deadliest in year in the province.

A Taliban stronghold, Helmand provided a key source of income for the restive insurgency —  opium was the dominant cash crop. In February 2010, coalition forces launched an all-out assault on the city of Marjah, an opium hub in the Taliban’s southern heartland. Its roads and alleys were heavily mined, as were the surrounding fields, and it was defended by die-hard Taliban fighters who flooded the area ahead of the U.S. Marine-led coalition advance.

Related: 5 Incredible Firefight Photos From One Of Afghanistan’s Deadliest Provinces »

What follows are four pictures of the first major operation of the Afghanistan troop surge, taken by Associated Press photographers David Guttenfelder and Brennan Linsley. The images underscore the danger facing American troops and their allies, as well as the courage and resolve required to overcome such odds.

A Marine with 3rd Battalion, 6th Marine Regiment leaps over a wall during a firefight as Taliban fighters open fire during a Feb. 15, 2010, gunbattle in the town of Marjah.

AfghanistanAssociated Press photo by David Guttenfelder

A wounded Marine is rushed to a waiting Black Hawk helicopter for casualty evacuation in Marjah, on Feb. 14, 2010. The soldiers of Task Force Pegasus supported U.S. and coalition forces fighting to break the Taliban’s hold on the city.

AfghanistanAssociated Press photo by Brennan Linsley

Marines from 3rd Battalion, 6th Marine Regiment open fire on Taliban positions in Marjah during a Feb. 15, 2010 firefight.

AfghanistanAssociated Press photo by David Guttenfelder

Marines and Navy corpsmen huddle around a pair of wounded Marines, shielding them from the dust kicked up by a helicopter during a casualty evacuation on Feb. 15, 2010 in Marjah.

APTOPIX AfghanistanAssociated Press photo by Brennan Linsley