TAIPEI—Taiwan opened a de facto embassy in Lithuania on Thursday in a diplomatic breakthrough, brushing aside Beijing’s strong opposition to the move. The Chinese regime demanded in August that the Baltic state withdraw its ambassador to Beijing and said it would recall China’s envoy in Vilnius after Taiwan announced its office in the city would be called the Taiwanese Representative Office in Lithuania. Other Taiwan offices in Europe and the United States use the name of the city Taipei, avoiding a reference to the island itself. The Chinese regime claims the island as its own, despite the fact that Taiwan is a de facto independent country, with its own military, democratically-elected government, and constitution. The Chinese regime has stepped up efforts to get other countries to limit their interactions with Taiwan, or cut them off altogether. Only 15 countries have formal diplomatic ties with Taiwan. Beijing has also been angered by …