The plan drafted by Benjamin Netanyahu and Ehud Barak to contain the fallout from May's raid on a Gaza-bound flotilla has run aground.

This week, it emerged that Jacob Turkel, who chairs the committee investigating the raid, is negotiating an agreement with the prime and defense ministers over expanding the panel's authority. This announcement represents the start of a slippery slope, one that could entangle Netanyahu and Barak more than they had expected.

The government's original plan called for splitting the investigation into two parts, with the substantive (and dangerous ) portion of the probe falling between the cracks. The Turkel Committee's mandate was deliberately crafted to be toothless: a group of scholars engaged in learned debate over whether the raid complied with international law. An examination of the government's functioning - along with other potentially lethal ideas like subpoenaing witnesses and seeking expert advice - was left outside the panel's purview.

Meanwhile, Israel Defense Forces Chief of Staff Gabi Ashkenazi set up a military inquiry headed by Maj. Gen. (res. ) Giora Eiland. Eiland is the only official with the authority to question soldiers and officers. But even he is limited: Some of his work will rely on internal probes performed by the navy and its commando unit.

During the Goldstone Committee's inquiry into last year's Gaza war, Barak sanctified the principle of protecting soldiers from investigation. The defense minister can thus take pride in the fact that Turkel's committee has maintained the halo of sanctity around this principle.

Turkel's panel will not be a repeat of the Winograd Committee, whose probe of the Second Lebanon War dragged on and on: The flotilla raid is far less complex, and its failings are less serious. But it seems the inquiry will be far less pleasant for Netanyahu and Barak than they had planned.