By Hatem Maher INGLEWOOD, California June 15 (Reuters) - Whistles drowned out parts of Iran's national anthem while other fans sang along, setting the tone for a World Cup opener that often felt more significant for political allegiances than the football on show. Before a crowd of more than 70,000 in Los Angeles, home to the world's largest Iranian diaspora, supporters waved flags, chanted and revealed starkly different loyalties as Iran fought back twice to secure a 2-2 draw with New Zealand on Monday.