The plan...

Israel set war plan more than a year ago Strategy was put in motion as Hezbollah began gaining military strength in Lebanon

"Of all of Israel's wars since 1948, this was the one for which Israel was most prepared," said Gerald Steinberg, professor of political science at Bar-Ilan University.
......
More than a year ago, a senior Israeli army officer began giving PowerPoint presentations, on an off-the-record basis, to U.S. and other diplomats, journalists and think tanks, setting out the plan for the current operation in revealing detail. Under the ground rules of the briefings, the officer could not be identified (from article)