Pierre Elliott Tru­deau used to complain, as most leaders do, about journalists trying to pry into his personal life. It’s none of our business, he’d say. And most of us agreed, shied away and gave him a break, as we did with John F. Kennedy.

But when you read the new Trudeau bio, Just Watch Me: The Life Of Pierre Elliott Trudeau 1968-2000 by John English, you understand why there are those who say we ought to stretch our noses.

The book’s big breaking story, in a nutshell, is How the Babes Ran 24 Sussex. There’s Margaret and Margot and Barbra and Kim and Gale and Liona — and I’ll stop there.

The book might well have been called “Just Watch Them.” They impacted PET’s election timing, his grand strategies, his moods, his decision-making. In 1977, the Liberals had a big lead in the polls and we in the fourth estate wondered why the PM didn’t push ahead with a campaign.

Now we find out. The story was: Maggie Puts Kibosh On Campaign. She stressed Pierre out so much that it cracked his vaunted mental discipline. He couldn’t focus enough to run an election. He waited until 1979 and lost to Joe Clark.

This isn’t sensationalism. English is a sober-minded scholar who had access to Trudeau’s private papers. A former Liberal MP, he has written an illuminating book, the second of a two-volume study.

It relates how actress and peacenik Margot Kidder helped convince the PM to launch one of his major initiatives — his international peace mission of the early 1980s. In talks at a black-tie dinner in Washington, she lit into Ronald Reagan’s senior troglodytes with all kinds of anti-nuke volleys. Trudeau urged her on via a thigh squeeze for every direct hit.

Many observers have said Trudeau was Canada’s Kennedy. This books adds another point of comparison. Each leader was unremittingly flirtatious and each leader got a great break from the reticent media.

Are wives and romances fair game for the fourth estate? Judging from this book they should be. The power behind the throne can’t be ignored. Just recently we saw how Laureen Harper masterminded her Stephen’s variety show coup — the piano and song act at the Ottawa gala.

There was no attempt to hide that news.

But nothing can quite match the work of Aline Chrétien. While her little guy was fast asleep one night, she awoke in time to find an intruder at the bedroom door, knife in hand. She may well have saved his life. Just another example of gal power.