Mike Pompeo can cancel the order of additional letterhead. Donald Trump has chosen to promote from within for his new national security adviser and to let Pompeo run things from his perch at State. Trump made the announcement on Twitter, natch:

Robert O’Brien had landed on observers’ short lists for likely candidates to replace John Bolton, who left the national security adviser position last week. It’s a solid choice in that sense, one of continuity rather than a “team of rivals” pick as Bolton arguably was. He has a lengthy track record of service in the diplomatic arena, having worked under Bolton at the UN during the Bush administration but also with Secretaries Susan Rice and Hillary Clinton during the Obama administration. In this administration, he’s mostly known for his A$AP Rocky shuttle diplomacy, but O’Brien has much more substance than that.

That expertise will no doubt make Capitol Hill more comfortable with the direction of foreign policy under Trump. One has to wonder how it will play with both the MAGA non-interventionists and the GOP’s still-significant Bolton-friendly crowd, however. This looks more like a middle-of-the-road establishment pick than the kind of out-of-the-box thinking both sides wanted from Trump (in very different ways, of course). O’Brien might be cut from the same mold as Bolton, but one would suspect he wouldn’t have lasted long with the Obama administration if he was. He’s certainly not going to bring a Rand Paul approach, either.

It also seems at first blush to be an extension of Pompeo’s influence rather than an expression of Trump’s own vision. O’Brien doesn’t have the resumé of someone bringing in his own constituency to the job in the way that Bolton did, or for that matter H.R. McMaster did. While O’Brien has a significant track record at State, he’s not been setting policy there. If this is an extension of Pompeo’s authority, then perhaps O’Brien is meant to be a conduit for Kellyanne Conway’s suggestion that Pompeo fill both roles. This might be the next best thing.

At any rate, O’Brien will need to hit the ground running on his newly expanded portfolio. Trump has to decide between the Boltonist and Paulist options with Iran after the bombing of Saudi Arabia’s oil infrastructure. For now, Trump is taking the more cautious route of expanding sanctions:

CBS News national security correspondent David Martin said the most urgent order of business for Pompeo will be to discuss the installation of better air defenses around the Saudis’ oil facilities, which have suddenly proven vulnerable to attack.

U.S. intelligence agencies were caught flatfooted, never expecting Iran would be so bold as to attack Saudi Arabia directly. A U.S. official told CBS News the U.S. has identified the exact locations in southern Iran from which the drones and cruise missiles were launched at Saudi Arabia’s oil facilities.

It’s not yet clear what form that expansion will have, nor whether this is the extent of the public US response. Equally unclear, at least for now, is what influence O’Brien will really have on the answers to those questions.

Update: Added “breaking” tag, since this is legit breaking news.