The US administration denied Israel the right to maintain F-35 jets which she is about to purchase. The planes have to be flown to Italy every time they need maintenance. That bars Israel from using the jets in a war or any large operation which requires immediate maintenance.
At $130 million a piece, the planes will be anyway too expensive to risk them in combat. Israel eyes the jets mostly as the only way to spend US military aid which must be used to purchase American armaments. Israel just does not need that many American weapons and routinely uses part of the aid for the items which are only nominally military, such as packed foods.