Stephen A. Feinberg, a billionaire financier who is informally advising Mr. Trump on Afghanistan, is also looking into ways to exploit the country’s minerals, according to a person who has briefed him. Mr. Feinberg owns a large military contracting firm, DynCorp International, which could play a role in guarding mines — a major concern, given that some of Afghanistan’s richest deposits are in areas controlled by the Taliban. In 2010, American officials estimated that Afghanistan had untapped mineral deposits worth nearly $1 trillion, an estimate that was widely disputed at the time and has certainly fallen since, given the eroding price of commodities. But the $1 trillion figure is circulating again inside the White House, according to officials, who said it had caught the attention of Mr. Trump. Great idea Mr. President, invade a country and take their wealth. What could go wrong? Make America Great Again!