Would the PNTBT have even mattered? According to wikipedia it banned all tests except those underground - which arguably this excavation would have been.
Sure. Both the USSR and the USA had "peaceful" nuclear programs until the 1996 PNE treaty, which banned those as well and was also when this canal project was declassified.
Could you imagine someone taking these programs exclusively on good faith? "I don't see how placing hundreds of warheads near Moscow could possibly be related to first strike strategies. This all looks perfectly normal. Israel isn't America's Cuba in cold war politics, what kind of crisis could possibly arise from the placement of these warheads?"
Some day our ancestors will find all this cold war stuff hilarious.
The Cuban Missile Crisis precipitated a withdrawal of U.S. nuclear ballistic missiles from Turkey, but the U.S. kept its nuclear gravity bombs at Incirlik Air Base, which remain there today.[1] I don't think storing nuclear bombs in Israel would have been considered a substantial change in posture considering that Turkey, unlike Israel, actually bordered the Soviet Union.
Would the PNTBT have even mattered? According to wikipedia it banned all tests except those underground - which arguably this excavation would have been.