So a long time ago, there were two countries named Iran and Iraq. They didn't like each other very much and they started a big fight called the Iran-Iraq war.
Israel was not actually part of this fight and didn't like either country very much. But, they did help one side secretly.
The country Israel was helping was Iran. They gave them weapons and other things to help them fight better against Iraq. They did this because they didn't like Iraq and thought it would be better if Iran won.
This made some other countries very unhappy and they got mad at Israel for helping. But Israel kept doing it anyway.
In the end, the war ended without any clear winner, but Israel's secret help to Iran definitely had an impact on the fighting.