<h1>Global Markets Tumble as US Tariffs Spark Retaliation; European and Asian Shares Hit Hard by Trade Tensions</h1> Global shares declined amid concerns over tariffs imposed by President Trump on key US trading partners. European markets saw notable drops, with France's CAC 40, Germany's DAX, and Britain's FTSE 100 all falling over 1%. US futures indicated a downward trend, while Asian markets, including Japan's Nikkei and South Korea's Kospi, also experienced significant losses. The tariffs, targeting imports from Canada, Mexico, and China, prompted retaliatory measures from Canada and Mexico. Meanwhile, SoftBank announced a joint venture with OpenAI, and a report from a Chinese company, DeepSeek, on AI developments affected technology shares. The US Federal Reserve maintained interest rates, and energy prices rose.