Who cares how Iran is ruled? After the fall of Iraq, the prevailing mess in Afghan and a near collapse Pakistan, Iran is the only remaining island. India's better ties, will also indirectly help US in case things go out of hand, as they are already on a lost war. If it helps develop better relations, favorable regimes and friendly fuel, whats the harm? US senators may be concerned, but its their govt.'s duty to explain them. India shud stick to 123 as well as the pipeline.
