IIRC, the USSR also planned but did not execute a nuke first strike on the USA in 1967. In the 1980s I was briefed that the Politburo was effectively deterred by Israel’s nuke capability. The Russkies knew that Israel had a plan to deliver a nuclear second strike to Russia using F-16s if required.
I don’t know about the F-16s.The range of the initial variants would have been very poor to even get to Armenia or Azerbaijan,which were the nearest Republics.The F-4 could do that(Israel had them in the 70s itself) with a small payload,one way -the F-15 could as well.Ballistic missiles are another issue.