There is an ongoing cold & hot war between Hamas and Israel. Israel maintains checkpoints in the West Bank, and continues to build settlements, while leaving Gaza alone. Hamas undermines West Bank peace by murdering Fatah members, and not negotiating with Israel, claiming they want to ultimately fight all Jews in the world. Furthermore, Mahmoud Abbas in the West Bank joined Hamas in a unity government.
I think you are mistaken about who started the current fighting. In short, among the backdrop of relative calm: 3 Israelis youths were murdered, Israel searched the West Bank, and arrested numerous Hamas individuals, among other suspects. An Arab boy was murdered, Israel arrested numerous Israeli suspects. Hamas begins firing rockets from Gaza. Then Israel began responding with air attacks in Gaza.