In recent months they've been pouring a lot of concrete at the al Udeid air base in Qatar. The giant facility used by US Air Force units has added a 13,000-foot runway, as well as ammunition dumps and a tent city able to house thousands of troops.
Military analysts surmise that the Pentagon is upgrading the Qatar installation so it can serve as a command post for any US attack on Iraq. Presumably other possible launching pads for anti-Iraq action in the region are receiving similar improvements.
"I'd like to get a look at some of those air bases in western Turkey," says John Pike of Globalsecurity.org, a think tank that obtained satellite photos of al Udeid this week.
As the work in Qatar shows, the giant machine of the United States military is moving, slowly but inevitably, toward completing preparations for war with Iraq. That doesn't necessarily mean fighting is imminent. The White House appears still far from picking a date certain for invasion.
Nor does it mean war plans are set in stone. Much has yet to be decided.
But amid the news leaks about possible troops levels, strategy, and timing, a pattern appears to be emerging.
Officials may have moved beyond the extreme military options a massive quarter-of-a-million troop effort on the one hand, and a small special operations strike on the other.
They're now likely focusing on something that might be defined as either Gulf War Lite or Afghan War Plus a mix of conventional force and lightning Special Forces strikes designed to oust Saddam Hussein's regime.
"The good news is they are seriously planning," says Gary Schmitt, executive director at the Project for the New American Century, who believes conflict with Iraq is clearly coming.
One Iraq war option that received public notice earlier this summer was a massive operation proposed by Gen. Tommy Franks, commander in chief of Central Command (CentCom). It involved upwards of 250,000 troops and months of deployment. It was, essentially, an extension of the Gulf War, a package of deployment plans that CentCom officers have been practicing and playing out in war games for over a decade.
A second plan, attributed to former White House security adviser Gen. Wayne Downing, involved lightning strikes by Special Forces units in conjunction with Iraqi opposition troops, backed up by US air power. On the surface it was very similar to the strategy that toppled the Taliban in Afghanistan.
If the first option seemed ponderous, the second may be too risky. Reports now indicate that the White House is focusing on a blend of the two. General Franks briefed President Bush Monday night on the latest plans, which call for upwards of 80,000 troops, plus a massive air campaign.
The existence of a planning process alone does not make war inevitable, of course. Sen. Joseph Biden (D) of Delaware, chairman of the Senate Foreign Relations Committee, said recently that he is convinced an attempt to oust President Hussein, if it comes, won't occur until after November, at the earliest.
But publicly the most hawkish US officials have been sounding increasingly impatient.
"Over time, the economic sanctions [on Iraq] weaken, the diplomatic effort gets a little tired," Secretary of Defense Donald Rumsfeld told the Senate Armed Services Committee last week.
A conventional attack on Iraq, say analysts, would consist of armored divisions punching into the country from Turkey in the north, and from the south. Presumably, the southern pincer would be launched from Kuwait, since Saudi Arabia has indicated its unwillingness to take part in an Iraq war.
The base at al Udeid in Qatar is widely thought to be the replacement for Prince Sultan air base in Saudi Arabia, long the US Air Force's regional command center of choice.
But the attack plan might not be conventional at all. It could be the so-called "Inside-Out option," in which US forces begin with a rapid move on Baghdad, bypassing entrenched forces in the rest of the country.
To be quickly successful, US forces would likely have to be able to mount 1,000 to 1,500 air sorties a day, analyst Anthony Cordesman of the Center for Strategic and International Studies told a Senate panel last week.
Iraq's air force is its weakest military link, noted Cordesman. In contrast, its ground forces still number over 400,000, and it would be "foolish" to assume that they would just crumble before a concerted US attack. In the Gulf War, defections did not occur until Iraqi units came under intense pressure.
"Saddam has been in power during the entire life of 80 percent of the Iraqi people. To say ... that there are factions that will not follow him is reckless and dangerous," said Cordesman.