While China would still have managed to get to its current level it would have taken it at least an extra decade had it not been for the US tech transfer during the Clinton years (and i am not just saying that to be on the 'blame it all on clinton' camp, which i am tired of, i am just stating the truth). The transfer of advanced guidance and miniturization tech literally took a decade off Chinese R&D and fiscal spending on that area.
It reminds me of when the Soviet spies Klaus Fuchs and the infamous Ethel and Julius Rosenberg's who stole US hydrogen-bomb technology that allowed the Soviets to detonate their first H-bomb in August of 1953! Without the spies the Soviets would still have got the thermonuclear bomb (after all they had detonated their first atomic bomb in 1949 .....again after 'lifting' some US info). However the H-bomb secrets enabled the Soviets to slice a year (expersts ay it was just a year) off their program ....and a year is still a lot.
China sliced off 10 years, and got on top of that advanced capability.
And unlike the Soviets (who still had to substantial resources in developing the engineering and industrial infrastructure to translate a theoretical design into an actual weapon) the Chinese basic got the whole nine yards! An analogy is that the Soviets got the plans for a Mercedes, and using the plans made their own mercedes clone using their own materials and their own expertise. All they stole was the blueprints. The Chinese on the other hand also got the plans for the mercedes, but they also got the tooling, most of the basic body frame, the engine, gearbox, and some of the more advanced innards! All the Chinese have to do is get their own upholstery.
The aboveis an extremely crude analogy but it should show what happened.
What China got from Israel is basically nothign they could not get themselves. Even the Israeli Lavi- Chinese J10 controversy, which is really not that big since both the US and Russia have ways of taking care of the Lavi; and as for the sale of Python-3 AAM missiles by Israel it should be noted that Israel now uses Python-4s. The same more or less applies for Russia. Russia knows China is its greatest threat for the next century or so! Hence everything Russia sells China is under strict FMS security deletion protocol (it is like the US selling military tech to iraq .....the stuff would be crap. A good example of this is the F-14s sold to Iran whihc had what i like to call 'engine deficiencies' LOL). The only nation Russia sells 'good stuff' to is India, and it has been that way for almost 2 decades now. China can obviously reverse-engineer the Russian and Israeli stuff (as it has been doing with the Israeli pythons and the Russian R-73s, but reverse-engineered AAMs are not as big a threat as ICBM technology. Personally i would rather face a nation with good AAMs than even basic nuclear ICBMs). As for Europe those guys (especially France) would sell their own grandma's soul for the right price, but i would not be too worried.
Anyways the biggest coup for the Chinese was the American technology.
It is time for the ABM defenses to be set up!
'nuff said!