Horowitz wrote this book because most management advice assumes things are going well. His didn't. He ran companies through the worst moments — near-bankruptcy, mass layoffs, firing executives he'd personally recruited, and making decisions where every option was bad.
The central message: the hard thing about hard things is that there is no formula for them. You can't look up the answer. You have to make the call, live with it, and keep going.
On firing people: do it with respect and speed. The person you're firing is not the problem — you are. You hired them, you managed them, and you failed to make it work. Own that. The conversation should be clear, short, and humane. Don't drag it out to make yourself feel better.
On The Struggle: every CEO goes through it. The moment when everything is falling apart, you can't sleep, and quitting seems rational. There's no trick to getting through it. You just don't quit.
On wartime vs. peacetime: a peacetime CEO optimizes and grows. A wartime CEO fights for survival. The skills are different and often contradictory. Knowing which mode you're in is the first decision.