Facing financial difficulties aggravated by the coronavirus pandemic, the southern African nation of Zambia appears headed for a default on debt owed to private investors. One of the world’s top copper producers, Zambia for years has been heavily indebted but now could get an undesired reputation for financial unreliability if a group of investors who hold $3 billion of the country’s eurobonds insist on payments that have come due. Zambia seeks a holiday of six months, but the bondholders’ final decision is pending.