“I don’t rule out any reason,” Mr. Barnea said. “And I’m sure there is more than one reason.”

All three actions this week further Mr. Netanyahu’s longtime goals.

As early as 2010, he sought to prepare for an attack on Iran’s nuclear facilities, but was stopped repeatedly by his own cabinet. He railed against the 2015 Iran nuclear agreement from its inception under President Barack Obama, contending it would allow Tehran to threaten Israel with atomic weapons within a decade’s time. And he has vowed for months to prevent Iran from establishing a conventional offensive threat to Israel from inside Syria.

The new war powers law, approved Monday on a vote of 62 to 41, was not written with the current skirmishes with Iran or the current prime minister and defense minister in mind, according to one of the measure’s architects.

Still, critics note that the corruption cases against Mr. Netanyahu, and the lack of security experience in his defense minister, Avigdor Lieberman, could raise questions about their motivations should they decide to take Israel to war.

And while the power applies only in “extreme circumstances,” the law does not define what those are.

Some experts said the new law may not have a dramatic effect. The prime minister and defense minister are unlikely to go to war without strong political backing and the support of the military and security agencies, some experts said, which have proven in the past to be cautious.

“A government cannot go to war, no matter what the law says, without a national consensus,” said Shlomo Avineri, professor emeritus of political science at the Hebrew University of Jerusalem. “Obviously a prime minister under investigation is limited by the kind of choices he can take, and they will be scrutinized even more than usual.”