What does “trust but verify” mean in English?

When you make a deal with someone you can’t fully control, you hope they keep their word — but you check anyway. “Trust but verify” means: yes, believe the other side, but still confirm they are telling the truth. It sounds friendly, but it carries a quiet warning. The phrase is used in politics, business, and daily life whenever a promise alone is not enough.

In the clip, the analyst compares Donald Trump’s approach to Iran with Ronald Reagan’s approach to the Soviet Union. She says: “what he kept talking about was trust but verify.” Her point is that any deal with Iran must include real inspection rights — not just promises. The phrase comes from a Russian proverb: “doveryai, no proveryai.” It rhymes in Russian. Reagan learned it from Suzanne Massie, a writer and expert on Russia, and used it again and again in nuclear talks with Mikhail Gorbachev in the 1980s. At one signing ceremony, Gorbachev smiled and said: “You repeat that at every meeting.” Reagan replied: “I like it.” You can use it in many situations outside politics: “He said he fixed the bug — trust but verify before we ship.” It fits both formal and casual speech, and people across news, business, and the workplace will know it right away.