The best clues to the Democratic Party talking points on the War in Iraq are usually found in the statements of Senate Majority Leader Harry Reid. Back when the war was going really badly, Mr. Reid was the first to pronounce it “lost.” This formulation persisted for several months, even as facts on the ground suggested otherwise. Curiously, few news outlets took much notice when “lost” finally disappeared from the senator’s grumblings.

His next gambit — the absence of political progress and the failure of sectarian reconciliation — possessed considerably less pith. But it had better legs and, even today, many Democrats persist in ignoring any and all signs of progress. (Less partisan sources have noted several promising moves, including the planned provincial elections in October, which should bring more Sunnis into the political process.)

Nevertheless, the tireless Mr. Reid has already moved on, calling attention to the economic costs of the war and the burden they are placing on a fragile economy.

This critique has been launched full-throttle into the echo chamber of Reid-friendly conventional wisdom. The oh-so-timely appearance of “The Three Trillion Dollar War” (W.W. Norton, 192 pages, $22.95), by Joseph E. Stiglitz and Linda J. Bilmes, iterates and reiterates this thesis ad nauseam, and is certain to get the chattering classes chattering about guns vs. butter.

Mr. Stiglitz, a Nobel laureate economist and former Clinton administration official, and Ms. Bilmes, a specialist in government finance, purport to uncover all the “hidden” costs of the war. These include everything from projected medical costs for returning veterans, to the difficult-to-quantify but — what the hell! — incremental cost of oil attributable to the conflict.

While the book predictably excoriates the Bush administration for confusing — if not dishonest — cost projections and budgeting, it indulges in plenty of fuzzy math of its own — not only on the cost of oil, but on the value of lost productivity due to military service, injury, and death. Economics, famously, is a dismal science, but “The Three Trillion Dollar War” is both dismal and thoroughly tendentious.

Much of their estimate of the cost of the war is contingent on the baseless assertion that the Iraq war was and is a primary driver of the recent oil price spike; as several economists have pointed out, the oil production lost as a result of the war accounts for less than 1% of global oil production. The Iraq war could just as easily be held accountable for the price spikes in gold, silver, copper, and most other commodities; in reality, commodity prices have spiked for a host of reasons, not least the growing demand from emerging economies such as China and India.

One of the more intriguing curiosities of “The Three Trillion Dollar War” is its conflation of the Iraqi campaign with the American effort in Afghanistan. The authors state their opposition to the Iraq invasion, but they are mute on Afghanistan. Nevertheless, the costs of both conflicts are tallied together and accounted for as one total war expenditure. In a chapter entitled “The Cost to Afghanistan,” they seem to reflect Democratic Party talking points that assert that Iraq distracted us from the real job of getting Osama bin Laden. If they believe that, why lump a worthy expenditure in with a bad? One can’t help wondering how much real support there is on the left for the Afghanistan effort. If President Bush granted them their wish and withdrew from Iraq immediately, would they support a redeployment of, say, 140,000 troops to Tora Bora?

The intellectual dishonesty of this book can be most clearly seen, however, in its discussion of general American defense spending. The authors note that defense expenditures have been “rising rapidly as a share of GDP — from 3 percent in 2001 to 4.2 percent in FY 2008.” They do cover themselves by admitting that this rise “is not a historic peak or anything close to it,” but they fail to disclose that defense spending was a whopping 13% of GDP in the halcyon 1950s! Even with two active wars and all the other antiterrorism measures, defense spending under President Bush is 50% lower as a share of GDP than it was under Ronald Reagan.

But wait. It gets better. “More troubling is that defense spending has been growing as a percentage of discretionary funding (money that is not required to be spent on entitlements like Social Security), from 48 percent to 51 percent today.” What this means, of course, is that in a federal budget where entitlement spending on Medicare, Medicaid, Social Security, and the like are exploding, the competition for the remaining dollars is intensifying and the war effort is getting a higher priority than the national parks. This might suggest the need for a book called “The 200 Trillion Dollar Entitlement Trap,” but it’s a safe bet that Mr. Stiglitz and Ms. Bilmes won’t be writing that one.

Mr. Willcox, a former editor in chief of Reader’s Digest, lives in Ridgefield, Conn.