President-elect Donal Trump’s selection of retired Marine Corps General James N. Mattis is a brilliant move. For the first time, we will have a Secretary of Defense who understands war–and also understands that much needs to change in the Pentagon if we are to win wars. General Mattis is a true warrior-scholar, someone who has read deeply in military history and theory and also has experienced combat at several levels of command. By choosing General Mattis, President-elect Trump has justified the hopes that so many of us have for his presidency.

I have only met with General Mattis once, when he was in command of Quantico, the base where the Marine Corps’ schools are located. He invited me down to discuss those schools and Marine Corps education generally. I proposed requiring “the canon” as a pre-requisite for Command & Staff College. “The canon” is the list of seven books which, if read in the right order, take the reader from the First Generation of Modern War into the Fourth Generation. General Mattis seemed favorable to the idea, but in the end nothing happened.

This may point to a need for an Undersecretary of Defense who understands how the Pentagon works and knows how to make it act even when it does not want to. Getting a bureaucracy to do what you want it to is a fine art, and I am not certain it is one in which General Mattis excels. The best man for that job would be Chuck Spinney. Spinney was one of the core members of the Military Reform Movement of the 1980s, and he spent his whole career working in the Pentagon. He knows both what needs to be done and how to get it done. A team of Mattis and Spinney would be unbeatable.

That team will face and imposing agenda. It begins with the subject of my last column, adopting a grand strategy appropriate to a world where we need and alliance of all states against non-state forces. In the 21st century, the state system itself is at stake. War between states is obsolete, because the losing state is likely to disintegrate into another stateless region, which will be a worse threat than was the original state.

This new grand strategy means that many of the systems and forces the Pentagon is paying for are obsolete, because they are useful only for wars between states. This is good news, because it means that, by ceasing to build a military museum, we can save a great deal of money.

That in turn is important in confronting the next challenge, the looming international debt crisis. We are either going to reduce defense (and other government) spending to the point where we can begin paying off the national debt, or we are going to have a debt crisis where the defense budget plunges to a small fraction of its current level. Prevention being better than cure, Secretary Mattis will be looking for programs to cut. At the head of the list should be the F-35, a poorly-designed, untested airplane on which we are expected to spend $1.6 trillion. Alternatives lie readily to hand: reopen the F-22 production line for the “high” end of the “high-low mix” and buy the excellent and cheap Swedish Gripen fighter/bomber for the “low” end of the mix. Other countries participating in the F-35 program should be allowed to purchase (and build parts for) the F-22 instead.

Then come reforms to make our armed forces more effective in combat. Two should be top priority. First, get the women out of all combat arms units. Their presence severely undermines unit cohesion because instead of becoming a “band of brothers”, the men see each other as rivals for the attention of the women. In combat, men will drop the mission to protect the women. And the women hold a whip hand over the men, because if a man does anything a woman does not like, including giving her an order, she can charge him with “sexual harassment”. The man is presumed guilty until proven innocent, and the case is handled, not by the chain of command, but by a commissar system biased toward the women. We need to reduce the presence of women throughout the military, but getting them out of combat units is essential, or those units will not fight.

We also need to move our Second Generation armed forces into the Third Generation, also known as maneuver warfare. On paper, the Marine Corps adopted maneuver doctrine in the early 1990s. However, it never institutionalized it, so it can’t actually do it. The new Marine Corps Commandant, General Neller, is trying to change this. The other three services remain purely Second Generation, reducing war to putting firepower on targets through highly centralized, slow-moving, predictable processes. We do not know whether even Third Generation state armed services can successfully carry on Fourth Generation war, but we do know that Second Generation militaries cannot.

That’s a full plate, and there is much more beyond this. If anyone can do it, General Mattis can–if he has someone by his side who understands how the bureaucracy works.