RAMALLAH, West Bank (AP) — The tenuous ceasefire in the Middle East has held up, sometimes barely, despite being shaken by repeated flare-ups over the past two months. But it is now coming the closest yet to blowing apart and sending the region back into full-scale war — and the detonator is Lebanon. Israeli strikes against Hezbollah militants in Beirut over the weekend brought retaliation from their key sponsor, Iran, which launched its first attacks against Israel since the ceasefire was