The real reason to doubt this story....is that Israel would never send weapons to the country that was hiding Nazis after WW II....no way Israel helps Argentina
While true that Menachem Begin did not like the British....there was a famous hotel bombing in the 1940’s that basically forced the British out of Israel...many believed Begin was involved....many Israelis at the time did not like the British because they were too coddling to the Arabs.
That’s not borne out by facts. Israel has had defense ties with Argentina and there’s nothing particularly wrong with that since the US, France and even Britain had strategic ties with that regime.
How else would you explain the presence of Israeli made warplanes and missiles during the Falklands war.
Begin was head of the Irgun, one of the two Zionist/Jewish terrorist groups active in Palestine between 1944 and 1947, both groups bombed and murdered and tortured British soldiers and civilians, as well as native Arabs and even Jews. The bombing of the King David hotel in 1946 was just one of many acts by both groups.
The other group, the Stern Gang, were so extreme that Abraham Stern actually met Nazi agents in 1941 to agree a plan where the Stern would sabotage the British in Palestine in return for all Jews in Europe being allowed a move to a Jewish state in German occupied Middle East (the Jews would get their homeland and the Germans would get ‘rid’ of European Jewry....)