Why did Nikita Khrushchev refuse to agree to Dwight Eisenhower's proposal to inspect each other's military sites?

President Dwight D. Eisenhower presents his "Open Skies" plan at the 1955 Geneva summit meeting with representatives of France, Great Britain, and the Soviet Union. The plan, though never accepted, laid the foundation for President Ronald Reagan's later policy of "trust, but verify" in relation to arms agreements with the Soviet Union.