I'm assuming you mean as SecDef.
In just a few weeks, he has driven "wokeness" and DEI out of the military. No small feat, as it had become ingrained in it's political structure since the Obama years and then codified by Biden. Lots of hurt feelings when you turn the military back into a meritocracy focused on lethality and not a weird social experiment. He has done that by laying down the law and firing whoever required firing without hesitation. It's all about merit now and the mission to increase lethality in the armed forces.
As a result, recruitment has skyrocketed. The US Army has fallen short of minimum requirements by 30-40,000 per year. They kept lowering standards and lowering recruitment goals to make the numbers work. Few red blooded American Patriots, (exactly who you'd want), wanted to join a force who's primary mission was wokeness, climate change and diversity. Now recruitment is at record levels with the military having to expand training programs to accept them all. And they need them badly.
For 4 years the military's motto was "Diversity is our strength". On day one, Pete said, fvck that, "Unity and focus on the mission is our strength". He wants a strong, lethal military, filled with warriors, and not to be squandered in "forever wars" that make the corrupt politicos rich at the expense of our sons and daughters. That also creates powerful enemies.
Did I mention Pete's a stud with big balls? I might have. He is exactly the right person at this time and place for the job.
But as you can imagine, flipping over the kitchen table while you're eating can create a lot of butthurt and the knives are out for him. That's okay, he's up for it. And.....his boss is behind him 100%.