A secret deal between Switzerland and the Palestinian Liberation Organization (PLO) from 1970 has recently come to light.

The Swiss newspaper Neue Zürcher Zeitung reports that then-Foreign Minister Pierre Graber offered to support Palestinians diplomatically in exchange for assurances the PLO would not carry out terror attacks against Swiss targets.

The precise details of the agreement will remain classified until 2020, according to Switzerland's statute of limitations. While the particulars are unclear, the mere existence of such an arrangement seems to run counter to the country's vaunted neutral status - a status which it takes so seriously that Switzerland refused to join the United Nations until 2002.

The move was taken after Palestinian groups carried out three serious attacks on Swiss air travel within about a year and a half.

In February 1969, four members of the Popular Front for the Liberation of Palestine (PFLP) attacked an El Al flight shortly before it took off from Zurich airport. They mortally wounded a pilot before an undercover security agent managed to stop them. A year later, a Swissair flight from Zurich to Tel Aviv was bombed, killed everyone on board.

Finally, that September, PFLP terrorists hijacked a Swissair flight to New York and forced it to fly to Jordan. The Jewish passengers were held hostage until Switzerland agreed to release four captured terrorists.

According to the report, the meetings between Switzerland and an internationally-designated terror organization raised ire in Israel, as well as in the US, UK, and Germany.

Some details in the case are still being investigated. In particular, a Palestinians man named Sufian Kaddoumi was arrested in connection with the Swissair bombing, but the Attorney General chose not to prosecute him. He never explained why, though the presiding judge repeatedly spoke of a "cloak of silence" over the case.

The meeting between the Swiss government and the PLO was arranged by long-time Israel hater Jean Ziegler, who was a member of the Swiss parliament at the time. Within diplomatic channels, he has encouraged the International Criminal Court in the Hague to charge Israel with war crimes and referred to Gaza as a "concentration camp."

He is now on the UN Human Rights Council's Advisory Committee.

NZZ asked Ziegler about his role in the affair, to which he replied that he had acted "in good faith," and that it was proper to assist terrorists in order to keep his own country safe.