‘No matter what our differences, most of us want the same thing,’’ the 69-year-old Massachusetts Democrat said in a video that highlights her family’s history in Oklahoma. ‘‘To be able to work hard, play by the same set of rules and take care of the people we love. That’s what I’m fighting for and that’s why today I’m launching an exploratory committee for president.’’Elizabeth Warren

Forty years ago, Chinese leader Deng Xiaoping and I normalized diplomatic relations between the People’s Republic of China and the United States, putting an end to three decades of hostility. This led to an era distinguished by peace in East Asia and the Pacific region. China’s spectacular economic growth , in conjunction with its continuing integration with the much larger U.S. economy, has enabled the two countries to become engines of global prosperity. Scientific and cultural exchanges have blossomed, and the United States has since become the top foreign destination for Chinese scholars and tourists. The 40th anniversary of this relationship is a testament to the ability of countries with different histories, cultures and political systems to work together for the greater good. Yet, today, this critical relationship is in jeopardy. Jimmy Carter