The s-400 is a joke. And then it will be run by Iranians, making it a bad joke.
The Israeli gas fields (by which I guess you mean the two chevron platforms in the Mediterranean) are mildly important to Europe, but barely register on Israel’s economy. The pipeline isn’t even started.
“The Tamar field, located 15 miles off Israel’s southern coast, meets 70% of Israel’s energy needs for power generation, according to the US energy company.”
https://ktvz.com/money/cnn-business-consumer/2023/10/10/israel-just-shut-a-gas-field-near-gaza-heres-why-that-matters/