US had a right to attack japan in wwII. Russia did not have a right to attack ukraine recently, because it did not exhaust diplomatic solutions.
you are correct, israel as an occupying force, does not have a right under international law to attack hamas within gaza.
yes israel treats the palestinians within its borders very poorly, its described as apartheid.
you can look up noam chomsky, norman finkelstein, chris hedges, illan pappe for times when israel has repeatedly violated the ceasefires. the israelis call it "mowing the lawn".