by John Rutherford, Producer, NBC News, Washington

Army Spec. Alex Jimenez of Lawrence, Mass., was promoted to sergeant on Jan. 7, but he wasn't around to accept his promotion. Jimenez, 25, is one of four Americans listed as missing and presumed captured in Iraq. Jimenez and Pvt. Byron Fouty, 19, of Waterford, Mich., have not been seen since they were ambushed south of Baghdad on May 12, 2007.

"Nothing in my life has ever been like this," Jimenez's father told the Boston Globe. "I stay strong because I think Alex is not dead, but sometimes all I can do is cry."

Besides Jimenez and Fouty, two other U.S. soldiers are missing and believed held captive in Iraq. Spc. Ahmed Qusai al-Taei, 41, an Iraqi-American and Army translator, was kidnapped Oct. 23, 2006, in Baghdad while visiting his Iraqi wife, and Staff Sgt. Keith Maupin, 23, of Batavia, Ohio, disappeared April 9, 2004, after his fuel convoy was ambushed. Maupin was later seen on videotape, surrounded by masked men holding automatic rifles.

In past wars, by comparison, 78,000 Americans are still missing from World War II; 8,100 from the Korean War; 1,763 from the Vietnam War, and 125 from the Cold War.

"These are all guys in reconnaissance flights [during the Cold War] who were downed by the Soviets," the Pentagon's Larry Greer said.

To view tributes to service members who've died this year in Iraq and Afghanistan, click here and then click on the individual photographs, which include the following seven U.S. casualties from last week:

1. Marine Lance Cpl. James Gluff, 20, of Tunnel Hill, Ga.

2. Army Sgt. Michael Sturdivant, 20, of Conway, Ark.

3. Army Staff Sgt. Robert Miller, 24, of Iowa City, Iowa.

4. Army Pfc. Duncan Crookston, 19, of Denver.

5. Army Sgt. Tracy Birkman, 41, of New Castle, Va.

6. Army Sgt. 1st Class Matthew Kahler, 29, of Granite Falls, Minn.

7. Army Staff Sgt. Robert Wilson, 28, of Boynton Beach, Fla.

 

Washington Producer John Rutherford is a decorated Vietnam veteran. He posts a weekly tribute to service members killed in Iraq and Afghanistan.