Updated

LONDON -- 6:15 p.m. local time

This story is generating tremendous interest. Obama planned, but did not officially announce, a trip in Germany to Landstuhl  Medical Center, a hospital and treatment facility for injured U.S. military personnel near Ramstein Air Base. Landstuhl is the largest overseas medical facility operated by the Pentagon and is the principal treatment and early recuperation setting for those injured in Iraq and Afghanistan.

Obama called off the trip Thursday. At first, the campaign said it did not want to be accused of visiting the wounded troops as part of an overseas trip financed by the senator's presidential campaign, fearing it would  be received and subsequently criticized as using the wounded as campaign props.

The McCain campaign quickly criticized Obama, asserting it is never inappropriate to visit wounded U.S. military personnel and Obama's concerns about political attacks were unfounded.

The Obama campaign then said it was told by the Pentagon that the trip would be "perceive" as political and that became the basis for its decision to scuttle the trip.

The Pentagon denied this on-the-record and in a letter it sent to Obama before the senator canceled the Landstuhl visit.

To give everyone curious the full sequence of the statements on this matter, I list them here in their entirety and in chronological order.

Here is the first statement on the matter from Senior Obama Communications Adviser, Robert Gibbs:

"During his trip as part of the CODEL (congressional delegation trip) to Afghanistan and Iraq, Senator Obama visited the combat support hospital in the Green Zone in Baghdad and had a number of other visits with troops. For the second part of his trip, the senator wanted to visit the men and women at Landstuhl Regional Medical Center to express his gratitude for their service and sacrifice. The senator decided out of respect for these servicemen and women that it would be inappropriate to make a stop to visit troops at a U.S. military facility as part of a trip funded by the campaign."

Following McCain's criticism Obama's campaign released this statement from traveling military adviser, Maj. Gen. Scott Gration (USAF retired):

"Senator Obama had hoped to and every intention of visiting our troops to express his appreciation and gratitude for their service to our country.

We learned from the Pentagon last night that the visit would be viewed instead as a campaign event. Senator Obama did not want to have a trip to see our wounded warriors perceived as a campaign event when his visit was to show his appreciation for our troops and decided instead not to go."

Today, Brian Whitman, a Pentagon spokesman, said the following:

"As a sitting senator he obviously has an official interest in the well-being of our service members and how the wounded and ill are being treated and certainly is welcome to visit a military medical center any time that he wants. As you all know, we do have certain policy guidelines for political campaigns and elections and what is appropriate and what is not appropriate int those situations, but the Pentagon certainly did not tell the senator that he could not visit Landstuhl."

Whitman was asked if the Pentagon said the visit would be "inappropriate"

"The issue here is that if you are both a sitting senator and a political candidate -- when you are doing things like a visit to Landstuhl you need to do it in your capacity as a sitting senator or you have to do it with restrictions that apply to any other candidate out there that might be running for office that is not a sitting senator. So you have to be able to draw that distinction.

Whitman was then asked what restrictions apply to candidates.

"The military tries very had not to get involved in political campaigns. There are certain activities that are not appropriate -- conducting a campaign speech, for example, on a military installation is not something that would be appropriate to do. You also have the issue when you visit any hospital -- you have issues of patient privacy.

Whitman was then asked who was involved in discussions with Obama's campaign.

"It wasn't here. My understanding is either EUCOM (European Command) or Landstuhl themselves. We learned a few days ago that there was some interest in Sen. Obama going to Landstuhl and all we did was simply remind people that Sen. Obama is a sitting senator, and his visit would need to be done consistent with a sitting senator."

Lastly, the Pentagon released this letter today from the Undersecretary of Defense for Personnel and REadiness, David Chu, that explained the guidelines for Obama's potential visit. It was sent, the Pentagon said, to commanders at EUCOM (European Command) and top officials at Landstuhl.

The guidelines were listed as:

1. You can land at Landstuhl and any/all media can cover your arrival and departure.

2. You will only be allowed at the Hospital with ONE SENATE staffer and appropriate security.

3. The only media allowed to follow into the hospital would be a military still photographer. The photographer would have potentially shot pictures of Obama with hospital staffers, members of the military and any patients that would want to participate.

That's the official back-and-forth. Obama has just finished his press conference with French President Sarkozy and will soon be here. More posts upon his arrival.