The dramatic move to join the Hague-based court, which could pave the way for the Palestinians to sue Israeli officials over war crimes, came less than 24 hours after the UN Security Council rejected a resolution seeking to set a deadline for ending the occupation.
The resolution's failure was hailed by Israel as a success, but Palestinian president Mahmud Abbas quickly moved to sign a request to join the court, finally making good on a threat which has been in the offing for years.
The move drew a sharp reaction from the US State Department and a derisive response from Israel.
"We will rebuff this attempt to force diktats on us just as we repelled the Palestinian appeal to the UN Security Council," Israeli Prime Minister Benjamin Netanyahu said late yesterday, insisting the Palestinians had more to fear from the court than Israel.
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"It is the Palestinian Authority that has formed a unity government with Hamas - an avowed terrorist organisation that, like the Islamic State (group), carries out war crimes - which should be concerned about the ICC," he said.
"Today's action is entirely counterproductive and does nothing to further the aspirations of the Palestinian people for a sovereign and independent state," he said.
The ICC can prosecute individuals accused of genocide, crimes against humanity and war crimes, committed since July 1, 2002, when the court's founding treaty, the Rome Statute, came into force.
To become a party to the court, the Palestinians must sign and then ratify the treaty.
The request was signed by Abbas during a leadership meeting at his West Bank headquarters in Ramallah that was broadcast live on Palestinian television. At the same time, he also signed applications to join 20 other international conventions.
In 2009, the Palestinians appealed to the ICC to investigate alleged Israeli war crimes during the Gaza war over New Year 2009 but the request was never processed because Palestine was not considered a state party.