As the world marks the 17th anniversary of the 9/11 terror attacks, the Pentagon\u0026#039;s latest lowball estimate of just how much the so-called War on Terror has cost Americans is making headlines—despite independent analyses that have come up with far higher figures.\u0022The collective wars in Afghanistan, Iraq, and Syria have cost U.S. taxpayers more than $1.5 trillion since Sept. 11, 2001,\u0022 CNBC declared Monday, citing a Pentagon report (pdf) from March.However, after Secrecy News published a copy of that report last month, Stephen Schwartz of the Bulletin of the Atomic Scientists compared the Department of Defense (DOD) figure with the oft-cited $5.6 trillion estimate put out last year by the \u0022Costs of War\u0022 project at Brown University\u0026#039;s Watson Institute of International and Public Policy.And the National Priorities Project (NPP), though it currently estimates war spending at about $4.6 trillion since 2001, has been keeping a running tally for years:Total cost of war from 9/11 to now: $4.6 trillion and counting. #Sept11 https://t.co/P8iV8QWwZJ pic.twitter.com/fCK9vC7Oo8— National Priorities (@natpriorities) September 11, 2018Watson\u0026#039;s estimate, Schwartz pointed out in a pair of tweets, \u0022took into account costs for which DOD is not responsible and therefore ignores—including care for veterans, Homeland Security, and interest paid to borrow money to pay for wars.\u0022An independent 2017 estimate, which took into account costs for which DOD is not responsible and therefore ignores—including care for veterans, Homeland Security, and interest paid to borrow money to pay for wars—pegged the total cost at $5.6 trillion. https://t.co/hqYRMUxQAT pic.twitter.com/LLe1wJOP5X— Stephen Schwartz (@AtomicAnalyst) August 29, 2018The Watson report (pdf) also acknowledges that \u0022there are still billions of dollars not included\u0022 in its estimate, such as the costs of state and local government\u0026#039;s veteran care programs that aren\u0026#039;t subsidized by federal tax dollars and \u0022the gifts the U.S. makes in excess military equipment to countries in and near the war zones.\u0022And on top of the trillions of dollars in war spending, there are additional costs that aren\u0026#039;t measured in dollars. As the Watson report puts it:[A] full accounting of any war\u0026#039;s burdens cannot be placed in columns on a ledger. From the civilians harmed and displaced by violence, to the soldiers killed and wounded, to the children who play years later on roads and fields sown with improvised explosive devices and cluster bombs, no set of numbers can convey the human toll of the wars in Iraq and Afghanistan, or how they have spilled into the neighboring states of Syria and Pakistan, and come home to the U.S. and its allies in the form of wounded veterans and contractors. Wars also entail an opportunity cost—what we might have done differently with the money spent and obligated, and how veterans\u0026#039; and civilians\u0026#039; lives could have been lived differently.In a recent interview with Common Dreams, Lindsay Koshgarian, research director at the National Priorities Project, concluded that the \u0022United States has wasted $5.6 trillion on wars in Iraq and Afghanistan with nothing to show for it.\u0022Based on the Watson Institute\u0026#039;s findings, the NPP operates running counts of spending on post-9/11 care for veterans, homeland security, interest on war debt, and the military—as well as a trade-offs tool that details how the government could otherwise spend the money, such as by paying teachers more, generating clean energy jobs, and providing millions of low-income Americans with healthcare.\u0022Politicians routinely claim that progressive policies like Medicare for All or free college are unaffordable, but have let the war spending spree continue largely unexamined for 17 years,\u0022 Koshgarian added. \u0022Americans never got the chance to decide whether that $5.6 trillion should pay for war or popular domestic policies.\u0022Although, throughout three presidential administrations, the federal government has poured trillions of dollars into war, shipped thousands of soldiers overseas to never return, and left hundreds of thousands of civilian dead and wounded, Harvard economist Linda Bilmes wrote in a 2016\u0026nbsp;column for the\u0026nbsp;Boston Globe that \u0022the cost seems invisible to politicians and the public alike.\u0022The reason, she argued, is that unlike with past wars, when \u0022the government routinely raised taxes, slashed nonmilitary spending, and sold war bonds...[as] part of an explicit strategy of engaging the American public in the war efforts,\u0022 with the War on Terror, \u0022almost all of the spending has been financed through borrowing—selling U.S. Treasury Bonds around the world—leaving our children to pick up the tab.\u0022Despite the burdens on current and future generations—and Defense Secretary James Mattis\u0026#039; optimistic remarks to reporters ahead of his unannounced trip to Kabul last week—nearly 17 years after the United States invaded Afghanistan, the longest war in U.S. history \u0022continues without relent or purpose,\u0022 with approximately 14,000 American troops currently on the ground. As Afghan civilians demand peace and the International Criminal Court seeks a probe of alleged war crimes committed by U.S. forces and the CIA, warmongers like Blackwater founder Erik Prince continue to pressure President Donald Trump to pursue policies that will line the pockets of mercenaries and Americans weapons manufacturers.This post has been updated with additional comment from Lindsay Koshgarian.