By Steve Holland
BAGRAM AIR BASE, May 25 (Reuters) - It takes a combination of careful planning and cloak-and-dagger secrecy to transport the president of the United States halfway around the world into a danger zone while making sure almost nobody knows about it in advance.
Barack Obama's visit on Sunday with U.S. troops at Bagram Air Base - unannounced ahead of time - has been in the works for several weeks as White House officials looked for an opportunity for him to make his fourth and most likely last trip here as president.
Security concerns mean plans for such visits have to be kept within a very tight circle.
"It's something that you plan with maximum discretion. But again, we've done it several times, so in some respects it gets easier each time," said White House deputy national security adviser Ben Rhodes.
Obama's trip was the latest in a string of secretive missions overseas that began when Republican President George W. Bush discreetly left his ranch in Crawford, Texas and popped up in Baghdad to celebrate Thanksgiving with U.S. troops in 2003.
Bush went on to make other similar trips to Iraq and Afghanistan, and Obama repeated the practice once he took office in 2009.
EXPLAINING WITHOUT EXPLAINING
For the Afghanistan trip, country music star Brad Paisley, who caught Obama's eye when he performed in a July 4 celebration at the White House, was pulled off a summer tour so he could accompany Obama and entertain the troops at Bagram.
"He had just started a tour and he had to juggle a lot of stuff and had to try to explain it to people without explaining it to people," Obama told the troops with a smile.
Obama brought only a small group of aides with him, including Rhodes, White House National Security Adviser Susan Rice and senior aides John Podesta and Dan Pfeiffer.
A pool of White House reporters and photographers was informed on Friday about the trip and sworn to secrecy. The press group was spirited aboard Air Force One at Joint Base Andrews outside of Washington and was on the plane when Obama arrived late Saturday.
After a flight of more than 13 hours, lights were turned off and window shades were drawn for the landing.
The president, wearing an Air Force One bomber jacket, seemed to relish the surprise, telling the troops he had been in the neighborhood and "thought I'd drop by."
Usually some subterfuge is needed to keep U.S. troops from guessing what is going on. On Sunday, troops who were not in the loop were told they were preparing for a rehearsal of some sort.
Rhodes told reporters it helped that the visit took place over the long Memorial Day holiday weekend.
"We have to plan these things with a high degree of secrecy and confidentiality out of the security concerns in play," he said. "And that involves everything from how staff gets to Andrews, to how you all get there, to how the president does. It's not the same motorcade; it's not the same footprint." (Editing by Caren Bohan and Frances Kerry)