DUSHANBE (Reuters) - Iranian President Mahmoud Ahmadinejad, seeking to boost Tehran's weight in Central Asia, met the leaders of Tajikistan and Afghanistan on Wednesday to forge closer ties among the Persian-speaking states. But his talks with Afghan leader Hamid Karzai and Tajik President Imomali Rakhmonov, hailed by the three as a new era in their alliance, produced little substance apart from acknowledging each others' cultural proximity. "We are united by a common language, culture and religion. It's impossible to divide us by borders or talk about our differences," he told reporters in the Tajik capital Dushanbe after talks with Karzai...