Long-threatened tariffs from U.S. President Donald Trump have plunged the country into a trade war abroad — all while on-again, off-again new levies continue to escalate uncertainty.

President Donald Trump’s 25% tariffs on steel and aluminum imports came into force Wednesday, triggering an immediate reprisal from the European Union as the global trade war enters a new and perilous phase.

Reuters, the news and media division of Thomson Reuters, is the world’s largest multimedia news provider, reaching billions of people worldwide every day. Reuters provides business, financial, national and international news to professionals via desktop terminals, the world's media organizations, industry events and directly to consumers.