They are Arab soldiers from Egypt and Syria. (Jordan usually refrained from using direct propaganda like that.)

That's back from the old days when it was still politically correct to wear a uniform and announce that the Jews should be exterminated. These days wearing a uniform in a war is a violation of "peace activism" and hence the non-anti-Semitic Jew murderers now wear civilian cloths.

Also note that back in the day the military odds were reversed and the Arabs thought they could beat Israel in a conventional war.

The rest of the world thought so too which is why so few countries helped Israel originally. Czechoslovakia supported Israel openly in the beginning until the Soviet Union put a stop to that. There is a certain romantic idealism in the fact that Czechoslovakia, a country that well remembered being invaded by Nazi Germany would then try to help another country being invaded by Germany's former allies. Thank you, Czechoslovakia.