A week after Michael Flynn’s abrupt fall from grace, President Trump will smooth things over with a national security adviser that at least some people can agree on.

Called everything from a “warrior scholar” to the “rarest of soldiers,”, Army Lt. Gen. H.R. McMaster is an about-face from the divisive Flynn, who resigned amid the escalating controversy over his contact with Sergey Kislyak, Russian ambassador to the U.S.

McMaster, often described as the army’s own futurist, holds a complex view on technology, cautioning against technological hubris as a solution to modern warfare. “Be skeptical of concepts that divorce war from its political nature, particularly those that promise fast, cheap victory through technology,” McMaster wrote in a 2013 op-ed in the New York Times titled “The Pipe Dream of Easy War.” He continued:

“Wars like those in Afghanistan and Iraq cannot be waged remotely. Budget pressures and persistent fascination with technology have led some to declare an end to war as we know it. While emerging technologies are essential for military effectiveness, concepts that rely only on those technologies, including precision strikes, raids or other means of targeting enemies, confuse military activity with progress toward larger wartime goals.”

That same characteristic deep perspective appears to be on display in his controversial but largely well-respected book, Dereliction of Duty, about the failing of military leaders, particularly the Joint Chiefs of Staff, during the Vietnam war. McMaster’s academic streak is just one of the traits that paints him in stark contrast to Flynn, who is widely regarded as ideologically driven, particularly by anti-Islamic sentiment.

During an April 2015 symposium on Army innovation, McMaster expanded on the risk inherent in an overreliance on military technology. “The biggest risk that we have today is the development of concepts that are inconsistent with the enduring nature of war,” McMaster said. “What we see today is really an effort to simplify this complex problem of future war and to essentially make it a targeting exercise. The idea is that the next technology we develop is going to make this next war fundamentally different from all those that have gone before it.”

At a defense conference in London a few months later, McMaster emphasized that traditional manpower can’t be ignored in favor of flashy technological advances that appear to provide short-term gains. “[There is a] delusion that… a narrow range of military technologies will be decisive in future war,” he said. “Technology is the element of our differential advantage over our enemies which is most easily transferred to our enemies.”

McMaster is no technophobe, but he dismisses conceptions of the future of war that “cut against war’s political nature, war’s human natures, war’s uncertainty and war as a contest of wills.”

Notably, he also really, really hates PowerPoint. “It’s dangerous because it can create the illusion of understanding and the illusion of control,” McMaster told the New York Times. “Some problems in the world are not bullet-izable.” (Good luck telling that to the commander-in-chief.)

It’s too early to tell how McMaster will fit into Trump’s roiling inner circle, or perhaps the outermost circle of his concentric inner circles, but McMaster’s willingness to critique authority around issues of national security is likely to prove relevant.

As Middle East scholar and former U.S. Army officer Andrew Exum writes in the Atlantic:

“One thing that stands out in the book is the way in which McMaster criticized the poorly disciplined national security decision-making process in the Kennedy and Johnson administrations, and especially the way in which the Kennedy administration made national-security decisions by a small group of confidants without a robust process to serve the president.”

It’s not hard to imagine how the Army’s big picture thinker might extend that criticism to a president who prefers to craft decisions through a small cluster of loyalists, incorporating little outside input. It remains to be seen if Trump will bring McMaster fully into the fold or if he’ll just freeze him out like so many other administration officials who have expressed dissent.

Whatever role he ends up playing, McMaster will join Defense Secretary James Mattis and Homeland Security Secretary John Kelly to round out the trifecta of well-respected military leaders who have Trump’s ear.