Israeli military chiefs were last night locked in marathon negotiations to try to resolve the unthinkable: industrial action by the Israeli Air Force.
At least 100 of Israel's most senior and trusted pilots are, quite simply and utterly unprecedentedly, refusing to fly missions - because they are not being properly insured.
Worse still for the defence establishment in a country still formally at war with two of its direct neighbours (Syria and Lebanon) and obsessed by the threat from more distant enemies such as Iraq, the mutiny is threatening to spread to members of the ground forces.
The pilots taking action are all reservists - but in the Israeli military, because of the relatively small size of the standing army, reservists are absolutely critical to day-to-day operations. Already, military chiefs acknowledge, the action is playing havoc with training procedures and operational missions - which include continuing missions over south Lebanon, where Israel is engaged in a continuing mini-war with Hizbullah guerrillas.
Most critically, the pilots' decision to withdraw their labour crosses a psychological red line, breaching an unwritten contract between these most highly-motivated and highly-skilled servicemen and their military establishment, a contract that, no matter what the circumstance, the call to duty would never go unheard.
The dispute essentially revolves around the pilots' insistence that their insurance conditions, for injury or death while in uniform, be equivalent to that of their colleagues in the standing army.
"When I report for reserve service, I accept all the obligations of a pilot, including flying over Lebanon and anywhere else," said one of the striking pilots. "But I won't accept that, if something happens to me, my family will get less compensation than the family of a pilot in the standing army."
Israel's new Minister of Defence, Mr Moshe Arens, who took over the job only this week, has acknowledged the justice of their demands, but protested the "flawed thinking" that has brought industrial action.
Similarly, the army chief of staff, Gen Shaul Mofaz, yesterday urged the pilots to "stop the threats", but has refrained from court-martialling or taking other punitive action against the pilots involved.
As the pilots' representatives and their bemedalled bosses met last night to try to halt the dispute, the pressure was increased by reports that reservists in the ground-force combat units, alleging similar discrimination, were considering joining the protest.