CRUCIAL MOMENT NEARING.(MAIN)

Byline: STEPHEN J. HEDGES and DOUGLAS HOLT Chicago Tribune

WASHINGTON -- Approaching a pivotal battle with the Republican Guard outside Baghdad, U.S. military leaders are counting on a combination of superior tanks, artillery, swift maneuvers and a punishing aerial bombardment to keep the elite Iraqi divisions boxed in place, where they must fight or capitulate.

Some active and retired military officers and analysts believe a battle against the Republican Guard will be a crucial moment in the war. If the Guard divisions south of Baghdad can be overwhelmed quickly, they say, it would send a strong signal to Iraq's remaining military establishment that the end …