It is not easy to solve the puzzle called Benjamin Netanyahu. For a year and a half, he labored to change the image that (justly) clung to him during his days as prime minister - an image of unreliability and a lack of seriousness. And now, in a mere two minutes in the Knesset plenum, he has returned to being the old Bibi: the incautious, the irresponsible, the one who acts in haste and schemes, the panicker who sweats under pressure.

For a year and a half, he tried to persuade us that he loved the job of finance minister and planned to change Israel's economy. Therefore, he wanted to remain in this job until the end of his term in order to finish the work. But then, in two minutes, he blew it all to smithereens, as in the old fable: The scorpion stings the frog, and drowns.

Something bad happens to him when he scents the prime minister's seat. He gets dizzy. He wants so badly to be prime minister, now, this minute, that he is incapable of restraining himself and waiting. To his mind, the finance minister's job is too small for him. After all, when he is prime minister, he will be finance minister, foreign minister - and prime minister, as well.

This week's incident was not the first time that his "Bibi" persona has gone to his head. Six months ago, when there seemed to be a good chance that the attorney general would recommend indicting Ariel Sharon, thereby leaving the prime minister's seat vacant, Netanyahu lost his head and began to plan his seizure of the reins of power. During that period, he greatly reduced his economic activity and began devoting more time to politics.

Then, in August, during his speech on the budget, he stressed the cuts and the harsh measures and worked to torpedo negotiations on bringing Labor into the government. Now he wants us to believe him when he says his sole goal is to prevent civil war via a referendum. That is why he attempted a crude putsch whose goal was to embarrass Sharon and shake the government until it toppled - after which he could vault into the empty chair.

In reality, he always opposed the disengagement - because Netanyahu identifies with the settlers, with the extreme right. He does not want to concede an inch, neither in Gaza nor in the West Bank. From his standpoint, the world can go up in flames - just as long as we do not abandon Netzarim. That is how he acted when he was prime minister. In September, he replaced his chief of staff, Aviv Bushinsky, with Yehiel Leiter, an extremist settler, who is giving him bad advice - which also contributed to this week's fiasco.

For Netanyahu to leave the Finance Ministry at this precise moment would be an economic crime for which there could be no forgiveness. The reforms would be stalled, the privatizations would not go forward, the Economic Arrangements Law would be eviscerated and the budget would balloon. The banks are already rejoicing, the dockworkers are drinking toasts, the electric company workers are chortling. They know that in the future, it will much harder to implement the reforms that were cut short now.

Someone who is willing to abandon the economy and the budget in this fashion, who is willing to cast Israel into an economic and political maelstrom that will bring back instability, and all for personal reasons, is not fit to be a leader - not finance minister, and not prime minister.