(FORTUNE Magazine) – I WAS READING THE NEWSPAPER THE other day, which I still do because sometimes it's even more reliable than the Internet, and my eye happened to catch a story about the whole situation with Karl Rove. The writer was wondering why the President seemed so determined to stand by the fellow, who was clearly, at this point, creating 42% more trouble than he was supposed to. Like many things you read, it was a stupid question. A boss without a No. 2 is in deep dip.

My first CEO was Bart. He was a very good guy, friendly, smart, tough. Being in his presence was a joy. His No. 2 was Finster. Being in his presence was not always so joyous. Yeah, he was a pal and blah-blah-blah, but in the end he was there to keep Bart's plateful of agendas shiny and clear, and that was that. My next boss was Walt, who had Howie, who drank so much black coffee keeping the boss's motor running that he spent the best part of every afternoon in a very private place with Time magazine, sitting and thinking. Walt was pretty much at a loss then. CEO Ned, who followed, had Chip, who had the bad form to require a quadruple bypass at an inconvenient time, leaving his boss exposed to the coup that eventually brought him down. Today I've got a No. 2. And the nation's CEO has his jolly, clever Karl, who has been described in states both red and blue as the President's Brain.

God bless our No. 2's. Without them we would have to work in a completely different way, in that we would have to, you know ... work. Wonder why the President is not going to jettison his guy, no matter how bad things get? Here's what a No. 2 does that makes the world go round:

• Is always there: I'm a very busy person. In the mornings I have dentist and doctor appointments, and sometimes I need to get to the tailor, and studies show that a visit to the gym every day is a good idea. And then there's lunch, as well as the many meetings I must attend in order to sit there. During all these times of day, there is important business to be conducted. I can't miss a beat! That's why I rely on my guy to be in at the crack of dawn and still be hanging in there at close of day when it is time for me to explore business relationships over strong beverages.

• Talks to people: I don't know about you, but as I get older and more hirsute, I enjoy speaking with others less and less. Sometimes I have the feeling that my skin is being peeled off when I'm required to interface with somebody's face. That's why, when another human life form looms, either in person or on the phone, I very often turn to my guy and say, "You talk with him, Bud." And he does!

• Runs the staff: Managing other people is hard work. They have yucky personal needs. They care about their office space and vacation time and often have problems accomplishing the tasks set out for them. All that stuff gives me a headache. I'm the boss. The fellow in the next office? See him. He'll handle it.

• Tends to the knitting: I'm not a details person. But as anybody who is not an author of business books knows, God is in the details, not in the mission statement. The problem is, those nitsy duties mount up. On our President's To-Do list, for example, I bet there are a couple of big items: "Build Democracy in Uzbekistan," or "Keep taxes low for the hard-working middle class." At the same time, I bet Mr. Karl is looking at a pad with eight pages of detailed chicken scratching. There are days when, with a clear desk and an empty mind, I saunter over to my guy's office and find him staring with vertical hair at dozens of message slips. What a feeling--to be leading while others work!

• Does nasty stuff: We're not going to get into the kind of things the President's Brain has done for him over the years, but suffice it to say that everybody in that management structure was very proud of Karl and amused by his stratagems until very recently, when he was sort of caught with an entire fried egg spread over his face. That goes against one of the prime directives of the great No. 2: to remain in shadow and keep any taint of unpleasantness from the big guy.

• Knows what I'm thinking: Because you know what? I don't. I'm an executive. I execute. There are so many people and duties and things in front of me all the time, I have no idea what I think about most of them. That's why I need my man there, because he knows what I think about everything, and if he doesn't, I know I don't care about it.

• Takes the bullet for me: I'll be the last one to buy the ranch, you know. Because in the end, if it's between him and me, it will be my beloved No. 2 who will step into the line of fire. Which is why I love him and will do anything to keep him safe--until I can't anymore. I hope that day will never come. But if it does?

Oh, well. Man does not lead by brain alone.

STANLEY BING's latest book, Sun Tzu Was a Sissy: Conquer Your Enemies, Promote Your Friends, and Wage the REAL Art of War (HarperBusiness), is available at finer bookstores everywhere. He can be reached at stanleybing@aol.com.