Arabs imported countless of weapons from Soviet and European nations. But the narrative we normally accept is that they failed miserably utilizing them. Were there any "dangerous" weapons for Israelis then, which had potential to inflict serious damage, or even turn the tide if operated properly?
Some of my guess; AT-3 Sagger anti-tank missle, SA-6 Gainful anti-air missile both from Yom Kippur War.
EDIT: alot
EDIT 2: Maybe I should have used the word "effective". I presume Israeli intelligence had been very cautious for certain weapons they hadn't coped before. Considering Arab-Israeli conflicts were in the middle of Cold-War, there would have many Soviet weapons that technologically mesmerizing for its Western counterpart. I was trying to ask which weapon was the most "big deal" for Israel and Western intelligence. I presume "dangerous" is a right word because its about weapons.
The AT-3 represented a single system having a greater impact than the SA-6 ever really did, as the latter performed as part of a large integrated air defense network.
But I have some questions about your question;
What exactly does "most dangerous" mean?
How do you compare apples and oranges?
How can you compare the lethality of the Malyutka against a Centurion or M60A1 with that of the Kub vs an F-4 or A-4?
I don't really understand how this question can have an answer.
In general, the AT-3 was capable of being countered to a greater extent than the Egyptian air defense network ever was, combined arms tactics emphasizing mechanized infantry and artillery support, suppresive fire and using the terrain to mask approach largely negated the impact of the AT-3 during the latter parts of the conflict.
But this was well after the first wave of counter attacking Israeli armored forces were almost entirely destroyed by the missiles.
The Egyptian soviet made ADN was never really neutralized, barring when Israeli ground forces crossed the canal and started rampaging around the Egyptian rear lines destroying many SAM sites with tank cannon fire.
The IAF enjoyed success only when the Egyptians sallied forth at the behest of the Syrians, leaving the safety of their air defense umbrella.
Sources:
Maj. General William E. Depuy Implications of the Near East War on US Army Tactics and Doctrine, 1973-1974
Dunstan, Simon, and Kevin Lyles. The Yom Kippur War 1973: The Sinai. Oxford: Osprey, 2003.
Asher, Daniel. The Egyptian Strategy for the Yom Kippur War: An Analysis. Jefferson, NC: McFarland, 2009.