First, Hamas did not start the last flare-up in violence. See John Glaser's "Israel’s Latest Assault on Gaza: The Lie of Who Started It."
Second, the just-assassinated Hamas leader, Ahmed Jabari, was in the process of negotiating a permanent truce with Israel. See the Haaretz report "Israeli peace activist: Hamas leader Jabari killed amid talks on long-term truce." According to the daily newspaper, "[Israeli peace activist Gershon]
Baskin told Haaretz on Thursday that senior officials in Israel knew about his contacts with Hamas and Egyptian intelligence aimed at formulating the permanent truce, but nevertheless approved the assassination."I submit that Jabari's willingness to talk true and his assassination are no coincidence. Israel does not want to see Hamas evolve. It needs an enemy.
More things to keep in mind:
Gaza has been under an Israeli blockade for years. Needed goods are kept out.
Israel helped to make Hamas what it is today. Years ago it promoted the organization as an alternative to the secular Fatah. Why? To splinter the Palestinians. If Israel now considers Hamas a mortal threat, it has only itself to blame. This is a case of blowback.
Israel's partisans refer to Hamas's declaration of war on Jews in its charter as a reason for scoffing at the idea that real negotiations are possible with the organization. That charter may be put in perspective by noting the words of David Ben-Gurion, Israel's founding prime minister:
Why should the Arabs make peace? If I was an Arab leader I would never make terms with Israel. That is natural: we have taken their country.... We have come here and stolen their country. Why should they accept that?All Zionist leaders were aware of that fact.
Nevertheless, Hamas has distanced itself from the charter and has shown a willingness to talk, as we've seen.The Israeli response has been assassination, bombing, and ground invasion. It is not Hamas that has consistently violated cease-fires.
Finally, one need not condone the shooting of rockets into southern Israel to care about the context. In 1948 Zionist paramilitary forces drove Palestinians out of their villages in the south and pushed them into the Gaza Strip. Many Gazans are refugees or descendants of refugees of the Nakba. The violence may be inexcusable, but it is not unprovoked.
See this roundup of the violence from Mondoweiss.