TEL AVIV, Israel — The Israeli military has drawn up plans for a major ground invasion into Gaza to fully occupy the territory within a few months and establish military rule there, according to two people who reviewed the war plans. This comes as Israel has returned to war in Gaza, ending a two-month ceasefire last week and carrying out intensive airstrikes targeting Hamas officials that has driven up the death toll in the territory past 50,000, according to Gaza health officials.