First, America was hamstrung by political and other ;reasons which did not allow them to bring our full might to bear against the Republic of Vietnam. If the US Army had been allowed to just "go for it" and blast the Viet cong with our full capacity, political correctness and all that bunk be damned, then the outcome of the Vietnam conflict would have been substantially different. Your premise is flawed.
Your arguement is flawed because Vietnam created the politcal sitution that led to their victory.
What if United States didn't break Japanese naval codes or what if Germany was not decieved into believing the Allied landing would take place for from normandy beach? The allieds use dirty tactics to win World War 2. The viet Cong knew their military was outclassed so they resulted to a guerilla and propaganda style of warfare which led to them achieving victory.
In the case of Israel, they have the full backing of the US and all its military power. Israel also has much more modern weapons and defense capabilities than most of the other nations allied against them. Do you see the problem with your statement?
No because your argument does not match dates of the 3 wars in which I mentioned occured. Do you believe Israel had superior military technology PRIOR to the 3 wars it had with its neighbors or afterward?. Today Israel could easily mop the floor with any middle eastern nation that comes against it but that was not the case 50 years ago. America had its hands full with trying to stop the spread communism to have help Israel survive its rocky start as a new nation.
And just for your information, most Western military leaders at the outset of the first Israel/Arab believe Israel didn't have a chance of winning the war. Do some research! Nothing you said is as factual you would like it to be. Arabs bought their weapons from Russia who created better tanks than America until M1 Abrams was released in the mid 80's. The F15 and F16 was given to Israel the late 70's According to the military channel the Russian Migs were equal to American F series fighters and the Russies had built better tanks which they happly sold to Israel's enemies. Plus the Soviets gave Egypt sophisticated air defense systems with the ability to blow ANY Western made aircraft out of the sky.
Please do not confuse the high tech weapons that the US and Israel have today with the quality of weapons that were actually used at the time of Israel defending itself against destruction of multiple invading armies.