What is driving the current Israel-Gaza violence?

Explainer: Iran supplies Islamic Jihad with funding, weapons including long-range rockets capable of hitting urban areas, providing smaller faction, arsenal compatible with Hamas.

Islamic Jihad is the smaller of the two main Palestinian militant groups in the Gaza Strip, and is vastly outnumbered by the ruling Hamas group. But it enjoys direct financial and military backing from Iran, and has become the driving force in engaging in rocket attacks and other confrontations with Israel.
Hamas, which seized control of Gaza in 2007 from the internationally recognized Palestinian Authority, is often limited in its ability to act because it bears responsibility for running day-to-day affairs of the impoverished territory. Islamic Jihad has no such duties and has emerged as the more militant faction, occasionally even undermining Hamas' authority.
The group was founded in 1981 with the aim of establishing an Islamic Palestinian state in the West Bank, Gaza and all of what is now Israel. It is designated a terrorist organization by the U.S. State Department, European Union and other governments. Like Hamas, Islamic Jihad is sworn to Israel's destruction.

Israel's archenemy Iran supplies Islamic Jihad with training, expertise and money, but most of the group's weapons are locally produced. In recent years, it has developed an arsenal equal to that of Hamas, with longer-range rockets capable of striking central Israel's Tel Aviv metropolitan area. Air raid sirens went off in the suburbs just south of Tel Aviv on Friday, although no rockets appear to have hit the area.
Although its base is Gaza, Islamic Jihad also has leadership in Beirut and Damascus, where it maintains close ties with Iranian officials.