By Samia Nakhoul, Maya Gebeily, Tom Perry and Laila Bassam
BEIRUT, June 11 (Reuters) - Iran is waging a calculated campaign to preserve Lebanon as its last bastion of influence on the Mediterranean, tying the country's fate to a grand bargain with Washington as it seeks to end Hezbollah's war with Israel on its own terms, not Beirut's.
That effort is colliding with a historic U.S.-sponsored negotiating track between Lebanon and Israel aimed at ending decades of conflict along their frontier and redefining the balance of power in a country long caught between regional foes.