Retired Lt. Gen. Michael Flynn has been called “the best intelligence officer of his generation” and an “abusive,” “erratic” “right-wing nut.” There’s truth to both sides of this story. In any case, he seems an unpromising choice for the next president’s national security adviser.

First, the good news, though it turns out to be not as good as it may seem. Flynn was Gen. Stanley McChrystal’s intelligence officer at the Joint Special Operations Command and played a key role in boosting JSOC’s effectiveness at capturing and killing Taliban and al-Qaida fighters in Afghanistan—figuring out ways to fuse massive streams of data from several previously isolated intelligence agencies and making them available to troops on the ground.

However, as one intel officer who was involved in the feat told me, “JSOC is hyper-tactical at what it does. It focuses on killing targets. Flynn gained no experience at planning a military campaign and certainly none at strategic intelligence or national policy”—which is what a national security adviser deals with.

In 2012, Flynn was named director of the Defense Intelligence Agency, a sprawling bureaucracy of 16,000 officials, mainly career officers, and tried to whack it into a different shape, reorganizing its divisions so they dealt with specific issues and putting some of its people into the field as clandestine agents. He received encouragement from Gen. James Clapper, the director of national intelligence who put Flynn in the post to fix what had long been a moribund organization. But several officers say Flynn proved inept, trying to impose change from the top down, spawning resistance and dysfunction. (By comparison, CIA Director John Brennan crafted a similar reorganization in his agency but paired senior officials with down-in-the-bowels officers, giving both a say in how to make the changes, and it worked with little angst.) Some of Flynn’s moves also drew protest from Brennan himself, who saw the planned DIA clandestine ops as a power grab for the CIA’s turf.

Flynn also began publicly voicing criticism of some assessments by the wider intelligence community, including its views about fledgling jihadi groups after the killing of Osama Bin Laden (Flynn thought, in some ways correctly, that they underestimated the threat), which also rubbed superiors the wrong way.

“This was a classic case of the Peter principle,” says one former intelligence officer who was generally on Flynn’s side in these disputes. “He’d risen to the level of his incompetence.” Two years into Flynn’s three-year term, Clapper and the undersecretary of defense for intelligence, Michael Vickers, called him into a meeting and forced him to resign.

Some of Flynn’s former colleagues—including two who think that he was fired unfairly and that he’ll make a fine national security adviser—say that the dismissal embittered him. The Flynn we see today—America’s angriest general, screaming “Lock her up—damn right!” with an anti–Hillary Clinton crowd and tweeting “Fear of Muslims is RATIONAL”—bears little resemblance to the Flynn they knew. “I was mortified,” one ex-associate told me. “He’s always been hard to get along with,” a former senior intelligence officer said, “but the way he’s been behaving lately hits a new level.”

Many outside critics have denounced Flynn’s remarks on Islam as racist, but intelligence officers are at least as disturbed by his analytical shallowness. The violent discord within Islam is certainly one cause of jihadi terrorism, but there are many other causes, not least the breakdown of the Cold War’s world order, the resulting of centuries-old sectarian schisms, and the aggravation of these splits by Iran’s regional expansionism and by Russia’s desperation to retain a Middle Eastern outpost.

In this sense, it’s not merely wrong to see Islam as the root of the problem; it’s also dangerous. Intelligence analysts take pride in parsing the terrorist threat—and the roots of conflict where the threat has risen—into its various sects, tribes, militias, and nation-state supporters. Not only does this give policymakers an accurate picture, it also provides insight into what they can do—ways they could play one faction off another, or exploit some converging interest, or even just identify the least of the evils at hand. Simply to view the whole array of threats as “radical Islamic terrorism” is to miss opportunities for action. It also risks becoming a self-fulfilling prophecy, as once-feuding militias or nations join forces upon seeing that the United States government really is fighting a war not against “terrorism” or “violent extremism” but against Islam itself, just as the most radical clerics warned. (This is why President Obama doesn’t reduce these movements to the label that Donald Trump, Flynn, and Rudy Giuliani demand. It’s not that Obama is being “politically correct”; rather, he’s being strategically smart.)

Yet here is Flynn in a tweet of July 24, shortly after some terrorist attacks:

In next 24 hours, I dare Arab & Persian world "leaders" to step up to the plate and declare their Islamic ideology sick and must B healed. — General Flynn (@GenFlynn) July 15, 2016

The conflation of “Arab and Persian” leaders, as if they’re the same; the poor syntax; the implied shrug at the fact that 1 billion Muslims around the world, including many who deeply oppose terrorism, might read this tweet and take it as a provocation—this is not normal behavior from someone about to become the president’s national security adviser.

The national security adviser is the most important presidential appointee who does not face Senate confirmation, so Flynn will face none of these questions—nor any about his financial ties to Turkey (and how they might have motivated his call for extraditing Fethullah Gülen, the dissident cleric now living in Pennsylvania, who Turkish President Recep Tayyip Erdogan wants to try for treason) or to Russia.

In some administrations, the national security adviser focuses mainly on reconciling the views of the secretaries of state and defense, then presenting them as options to the president. (Retired Gen. Brent Scowcroft was the prototype of this approach with President George H.W. Bush.) In other administrations, the adviser focuses mainly on educating the president. (Condoleezza Rice, who was unable to control the feuding Cabinet secretaries, took this approach with Bush’s son, though he wound up influencing her as much as vice versa.) Flynn will likely do both with Trump. We don’t know how he’ll do the former job, as Trump hasn’t yet announced who those secretaries will be. As for the latter job, Trump seriously needs a strategic educator—he appears to know nothing about foreign policy, the military, or national security broadly speaking—but Flynn’s shortcomings are also severe, and his main qualification, as far as we’ve seen, is that he reinforces, and as a retired general legitimizes, Trump’s prejudices about Muslims and his oversimplified view of the terrorist threat.

It’s worth paying attention to what people say. Sometimes they mean it.