The JSF (and F-22, and somewhat the F-18 Super Hornet) take a very integrated approach. Unlike the F-16 and F-15 which Israel currently flies, radar, counter measures, other sensors are basically one system using antennas built all over the airframe, using a common computer system.

In the older approach they were standalone devices that could be individually replaced and modified.

Israel has a serious and real requirement to have unique systems. After all, the US arms pretty much everyone in the region, and it is NO fun being at the same level in combat.

You MUST have an advantage. An Israeli F-15/F-16 does not look, nor behave like a one the US flies. The radar and counter measures systems have been modified.

This means that dealing with them is harder, and that is a life saver for Israeli pilots, and the people they are defending.

The F-35 is going to be really problematic for them to do this, but I imagine they are going to do it anyway!

They also need to basically double efficiency in each iteration in order to see real cost savings.

The US and current partners have some real funding issues in the first couple of years of production.

That is why the want Isreal to buy them. Isreal wants them as fast as possible, which is perfect, it means they can kick production up, and someone is willing to pay for them, and it means every plane the US, UK, Canada, Italy, the Netherlands, and other partners buy is automatically cheaper.

The fact the Isrealis are willing to buy now, potentially could save the F-35 program in the long run, and save US taxpayers BILLIONS!

The US intends to buy on the order of 2000-3000 planes. Getting production up to speed now, means a cost savings of $5-10 million per plane. That means a potentail savings of 10-15 billion dollars over the life of the program. (There is an exaggeration in there, since the cost drop happens whenever they get production going faster, but the sooner you start it, the greater the savings, like compound interest on a mortgage).

It will help all the partner countries. Italy was supposed to take 4 planes this year and has cut back to 2. Canada is in a similar situation due to lack of funding. With every cut in production, the costs get higher and higher, and you end up in a spiral where the F-22 ended up and the original plan of maybe $80 mil a plane blossoms to $170-220 mil a plane, and suddenly instead of buying 1000 of them, you will be lucky if you get 220.

So this is actually a HUGE win for the US and all JSF partner nations. Isreal gets what it wants and needs as well, win win across the board.