According to the Jerusalem Post, Israel ran a mission into Syria to end a transfer of very lethal weapons to Hezbollah. It is believed the Russian jet was shot down by Syrian friendly fire killing st least 15 people. The Israeli mission was conducted at a military facility. 

Israel has a right to defend itself and this is an ongoing operation to prevent munitions from reaching Hezbollah. So, for as sad an outcome that this is for Russia, these types of strikes against Hezbollah is not unusual.

Why isn’t President Trump taking care of business and standing up for Israel’s right to defend itself. I am sure if Israel had it’s way there would be no casualties, but only destroyed weapons to prevent any escalation of the war by Hezbollah.