The annual military construction spending bill is not generally a big deal for Congress, which treats it as an opportunity to fund gyms and chapels at district military bases. But the bill’s funding for overseas military installations is worth scrutinizing for what it reveals about the Pentagon’s global plans. In fact, the version currently under consideration by the Senate contains some pointed criticism of how those plans are being handled.

The Defense Department has undertaken a radical reshuffling of its overseas bases in recent years under its Global Defense Posture initiative. Activities include reducing the number of troops permanently stationed overseas, consolidating bases and constructing new facilities to accommodate DOD’s reconfiguration of ground troops. The initiative also carries a $9 to $12 billion price tag.

But the Pentagon is making it hard to follow the money, lawmakers say. “DOD’s estimate for the cost of the global defense posture initiative significantly underestimates the total costs associated with restructuring DOD’s global posture,” reads the report for the FY 2010 military construction and veterans affairs bill. DOD is required to report to Congress each year on the initiative, which received $1.5 billion in the White House’s 2010 budget request. Yet, as the Government Accountability Office has repeatedly reported , DOD has failed to give Congress a complete list of overseas bases and other data that would help lawmakers get a realistic estimate of the initiative’s price. The fact that the Pentagon’s estimate hasn’t changed since 2004 despite the addition of several new projects also raises some questions.

Probably the biggest such project is the move of 8,000 Marines and their families from U.S. bases in Okinawa to the U.S. island territory of Guam. The cost of the project has swelled from $10 billion to at least $13 billion, according to the bill report, and Marine Corps officials have testified even that figure is likely a lowball. But due to DOD’s lack of “documentation and clarity on future plans,” the committee cut $270 million from the bill for Guam projects such as wharf and airstrip improvements.

Anyone who thinks oversight of overseas military construction projects is a minor point should remember the Kaiserslautern Military Community Center . This is the complex near Ramstein Air Base in Germany that ran millions of dollars over budget because DOD neglected to validate cost estimates and manage contractors. And then of course there's all those Iraq construction scandals . Just a little reminder that when it comes to sending taxpayer dollars overseas, out of sight should not be out of mind.