CARACAS, Venezuela (Reuters) - Venezuela's President Hugo Chavez on Sunday said he would have a nasty welcome waiting for U.S. forces he insists are preparing to invade his country -- arrows laced with Indian poison. The left-wing former soldier, who has ordered his military to train civilian reserves for a guerrilla war, including the use of bows and arrows, often accuses Washington of planning to invade to control Venezuela's vast oil reserves. U.S. officials dismiss his assassination and invasion charges as populist rhetoric meant to mobilise supporters before presidential elections in December. But they say Chavez is an anti-democratic threat...