Donald Trump, in a recent social media post on January 12, 2026, threatened to impose a 25% tariff on any country conducting business with Iran, effective immediately. This sweeping declaration targets nations like China, Iran's largest trading partner and the biggest buyer of its oil, and has global economic and geopolitical ramifications. The move comes amid intense anti-regime protests in Iran, which Trump has cited as a reason for increasing pressure on Tehran. However, this policy risks destabilizing a delicate trade truce reached between the United States and China in October 2025, which had aimed to de-escalate their protracted trade war by rolling back some tariffs and easing access to strategic resources. China has promptly reacted, with its Foreign Ministry spokeswoman Mao Ning stating firm opposition to unilateral sanctions and vowing to protect Beijing's legitimate interests, indicating potential retaliatory measures. For India, the tariff threat presents a diplomatic tightrope. While India has significantly reduced oil imports from Iran due to past international sanctions, it maintains trade relations, particularly in basmati rice, pharmaceuticals, and for regional connectivity projects. The new tariffs could further complicate India's efforts to balance its strategic partnership with Washington against its regional interests. Analysts are scrutinizing the enforceability and specifics of Trump's latest tariff threat, acknowledging his history of using tariffs to influence foreign policy, but also warning of potential negative impacts on American consumers and global markets.