The recent death of a Marine in Iraq exposed the fact the United States set up a firebase there, which in turn exposed the fact the Pentagon misrepresented the number of American personnel in Iraq by as many as 2,000. It appears a second firebase exists, set up on the grounds of one of America’s largest installations in the last Iraq war. Special operations forces range across the landscape. The Pentagon is planning for even more troops. There can be no more wordplay: America now has boots on the ground in Iraq. The regional picture is dismal. In Syria, militias backed by the Central Intelligence Agency are fighting those backed by the Pentagon. British, Jordanian and American special forces are fighting various enemies in Libya, which, as a failed state, is little more than a nascent Iraq likely to metastasize in its neighbors. But Iraq remains the center of what Jordanian King Abdullah now refers to as the Third World War. It is where Islamic State was birthed, and where the United States seems to be digging in for the long haul. Though arguably the story of Islamic State, Iraq and the United States can be traced to the lazy division of the Ottoman Empire after World War One, things truly popped out of place in 2003, when the US invasion of Iraq unleashed the forces now playing out across the Middle East. The garbled post-invasion strategy installed a Shi’ite-dominated, Iranian-supported government in Baghdad, with limited Sunni buy-in. Sectarian fighting and central-government corruption favoring the Shi’ites drove non-ideologues without jobs, and religious zealots with an agenda, together. Clumsy policy cemented the relationship. A senior Islamic State commander explained that the prison at Camp Bucca, operated by the United States, was directly responsible for the rise of the violent, theocratic state inside the divided, but then still largely secular Iraq. “It made it all; it built our ideology,” he said. “We could never have all got together like this in Baghdad, or anywhere else.” So, first came al Qaeda in Iraq, followed by its successor, Islamic State. Fast-forward through about a year and half of Washington fear-mongering (that caliphate, those lone wolves), as well as the terror attacks in Paris and Brussels, and America’s re-entry into Iraq moved quickly from a Yazidi rescue mission to advisors to air power to commandos to today’s boots on the ground. Even if Islamic State is destroyed (as every American leader or potential leader has promised), the problems in Iraq, Syria and virtually everywhere else in the Middle East would still plague the rest of the world. Islamic State is a response, and its absence would only leave a void to be filled by something else. The root problem is the disruption of the balance of power in the Middle East, brought on by a couple of regime changes too many. The primary forces that the United States are supporting to attack Islamic State in Iraq’s Sunni territories are Shi’ite militias. Though they have been given a new name — Popular Mobilization Units — that does not change who they are. One particularly horrifying example: A Shi’ite fighter asked his Instagram viewers to vote on whether or not he should execute a Sunni prisoner. Washington clings to the hope that the militias and the US administration are united against a common foe – the bad Sunnis in Islamic State. The Iranians and their allies in Baghdad, who are also supporting many of the same militias, are more likely to see this is as a war against the Sunnis in general. As for any sort of brokered settlement among the non-Islamic State actors in Iraq, if 170,000 American troops could not accomplish that in almost nine years of trying, retrying it on a tighter timetable with fewer resources is highly unlikely to work. It is unclear what solutions the United States has left to peddle anyway, or with what credibility it would sell them, but many groups will play along to gain access to American military power for their own ends. With no change on the horizon, it seems likely that President Barack Obama’s successor will be inheriting, in the words of one commentator, a “bold new decade-old strategy” that relies on enormous expenditures for minimal gains. The question that needs to be asked is: If war in Iraq didn’t work last time, why will it work this time? Peter Van Buren, who served in the State Department for 24 years, is the author of “We Meant Well: How I Helped Lose the Battle for the Hearts and Minds of the Iraqi People,” a look at the waste and mismanagement of the Iraqi reconstruction. His latest book is “Ghosts of Tom Joad: A Story of the #99 Percent.”