Israel is a state and its current military operations in the conflict are described as self defense. I have not found an Israeli government source justifying the actions as self defense, but other Western governments all used that term. Some examples:
President Biden of the United StatesFor example, according to the BBC:
"My expectation and hope is that this will be closing down sooner than later, but Israel has a right to defend itself when you have thousands of rockets flying into your territory," he told reporters at the White House.
German officials according toin DW:
Germany has fiercely condemned the rocket attacks by militant Palestinians from Gaza on Israel and underlined the Jewish-majority state's right to self-defense.
President Macron of Francean interview with Face the Nation, according to DWIsraeli PM Netanyahu said:
AccordingAnd I think any country has to defend itself. It has a statement released by the Elysee, the president said Israel had "thenatural right of self-defense. We'll do whatever it takes to defend itself" while stressing "his concerns aboutrestore order and quiet and the civilian population in Gazasecurity of our people and deterrence." We're trying to degrade Hamas's terrorist abilities and to degrade their will to do this again.