To borrow a line from Dennis Green, they are who we thought they were.

From his hospital bed, Dzhokhar Tsarnaev has acknowledged his role in planting the explosives near the marathon finish line on April 15, the officials said. The first successful large-scale bombing in the post-Sept. 11, 2001, era, the Boston attack killed three people and wounded more than 250 others.

The officials, who spoke on condition of anonymity to describe an ongoing investigation, said Dzhokhar and his older brother, Tamerlan Tsarnaev, who was killed by police as the two attempted to avoid capture, do not appear to have been directed by a foreign terrorist organization.

Rather, the officials said, the evidence so far suggests they were “self-radicalized” through Internet sites and U.S. actions in the Muslim world. Dzhokhar Tsarnaev has specifically cited the U.S. war in Iraq, which ended in December 2011 with the removal of the last American forces, and the war in Afghanistan, where President Obama plans to end combat operations by the end of 2014.

Obama has made repairing U.S. relations with the Islamic world a foreign policy priority, even as he has expanded drone operations in Pakistan and other countries, which has inflamed Muslim public opinion.

Bad news for liberal narratives in one sense, but good in another: They’ve been grasping for ways to say “it’s not them, it’s us” and now they’ve got an easy one, Obama’s stewardship of Afghanistan notwithstanding. Beats the current leading theory about Tamerlan Tsarnaev possibly having taken too many punches to the face, no?

As for how they learned to make the bombs, watch Pete Williams below. Truth, or a lie designed to throw the feds off the scent of whoever might have trained them? Well, go back to this post from last Tuesday, two days before the bombers were identified. Intelwire had already raised an eyebrow at the fact that pressure-cooker bombs were used, since there had been articles in “Inspire” on how to build that sort of device. The Jawa Report also noted that Naser Jason Abdo, the would-be Fort Hood bomber, got caught with pressure cookers and other bomb materials in his hotel room when he was pinched in 2011. Also found in the room: A copy of “Inspire.” I remember people giggling when the magazine debuted because the bomb-making instructions were entitled, “How to Make a Bomb in the Kitchen of Your Mom,” but it worked. The man responsible for it, Samir Khan, is long since dead in a U.S. airstrike — but not as the primary target. He was killed by the same missile that took out his pal, Anwar al-Awlaki, whom some think came up with the idea for “Inspire.” Bottom line: Yeah, it’s quite possible that Tsarnaev’s telling the truth about how they learned bombmaking. Abdo apparently took the same path. He just never made it as far as they did.

Exit question, in the spirit of lefty fingerpointing at tea partiers: Does this mean the anti-war movement’s guilty by association?

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Update: Possibly significant:

Tamerlan Tsarnaev, the elder brother suspected in the Boston Marathon bombings, bought two large pyrotechnic devices in February from a New Hampshire branch of a national fireworks chain, according to executives at the chain’s parent company.

William Weimer, a vice president of Phantom Fireworks, said the elder Mr. Tsarnaev on Feb. 6 purchased two “Lock and Load” reloadable mortar kits at the company’s Seabrook, N.H. store, just over the border from Massachusetts. Each kit contains a tube and 24 shells, he said. Mr. Tsarnaev paid cash for the kits, which cost $199.99 apiece.

Cops are wondering if they used the powder from the fireworks to power the bombs, but the manufacturer thinks there wasn’t enough of it in two kits to generate explosions that big. Even so, go read this Boston Globe report from late March about a mysterious series of explosions in Hanover, Massachusetts involving homemade devices and “flash powder.” Actual quote from a local cop: “It appears there is someone exper­imenting with making these devices.” The explosions happened on March 12 and 15; on March 20, a friend of Dzhokhar Tsarnaev tweeted to him that he’d heard he’d been “poppen fireworks.” Hmmmm.