Israeli ground forces crossed into southern Lebanon early on Tuesday, marking a significant escalation of an offensive against Hezbollah militants and opening a new front in a year-long war against its Iranian-backed adversaries. The incursion follows weeks of heavy blows by Israel against Hezbollah, including an airstrike that killed its long-time leader, Hassan Nasrallah, and seeks to step up the pressure on the group, which began firing rockets into northern Israel after the start of the war

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