JERUSALEM — A year after Hamas’ fateful attack on southern Israel, the Middle East is embroiled in a war that shows no signs of ending and seems to be getting worse. Israel’s retaliatory offensive was initially centered on the Gaza Strip. But the focus has shifted in recent weeks to Lebanon, where airstrikes have given way to a fast-expanding ground incursion against Hezbollah militants who have fired rockets into Israel since the Gaza war began. Next in Israel’s crosshairs is archenemy Iran, which supports Hamas, Hezbollah and other anti-Israel militants in the region.