LONDON — Yulia Tymoshenko, Viktor Yushchenko and Viktor Yanukovych were once called the "eternal triangle" of Ukrainian politics, but eternity is not what it used to be. One side of the triangle has disappeared.

Five years ago, when the Orange Revolution turned Yushchenko and Tymoshenko into democratic heroes, the villain of the piece was Yanukovych, the former communist apparatchik who tried to steal the 2004 election.

Yushchenko was a very weak president except in one area: his obsessive feud with his former ally, Prime Minister Tymoshenko, which all but paralyzed the government of Ukraine for five wasted years. It's likely that she bears as much of the responsibility as he does for this disastrous clash of personalities, but she is a much more vivid personality and an adroit politician, so the public blamed Yushchenko. Now he has lost the presidency in the most humiliating manner imaginable.