The events of March 1968 in Polish Peoples’ Republic unfolded against the backdrop of Soviet foreign policy objectives, its successes, and its failures. In June 1967 Israel – a U.S. ally – defeated Egypt, Syria, Jordan and Iraq in what is known as the Six-Day War. Moscow, humiliated by the defeat of its client states, responded by ordering the leaders of its Easter European satellites to break diplomatic relations with Israel. “Zionists” everywhere were to blame for the defeat – and they were to pay the price. As in the Soviet Union during the Great Purge, the communist party turned against its own, against the purported Zionist enemy within.
On direct orders from Moscow, Poland broke off diplomatic relations with the Jewish State in June 1967. By March 1968, factional struggles within the Polish communist party responding to Soviet directives took an openly anti-Semitic turn. They led to ever-harsher repression, censorship, police surveillance, and arrests.
Bitterly opposed to the Soviet occupation of their homeland, the people of Poland cheered the Israeli victory as a blow against their communist oppressor. Because Israel was seen as anti-Soviet, most Poles instinctively supported the Jewish State. They remembered that many Israeli political leaders and officers were former Polish soldiers in General Władysław Anders' Army, made up of Gulag survivors and deportees rescued from the Soviet Russia (1941-42). Poles of Jewish descent showed their pride and support for Israel by changing their Slavic first names to Hebrew. Official anti-Semitism of the communist party prompted broad sympathy for its Jewish victims. When communist censors closed down a famous nineteenth century play, Forefather’s Eve, for its openly anti-Russian sentiment, Poland’s university students erupted in protests. Many of their best-known leaders were marching against the regime that their parents helped establish.
See full text: https://march68.pl/
We also recommend broader analysis : http://wei.org.pl/files/manager/file-28c3e74e626008bb67d4e61c5f20e804.pdf