Why was the foreign policy of Harding and also Coolidge called isolationist?

Isolationism is a foreign policy chosen when a president (especially Harding and Coolidge) decides to keep other countries' problems at a distance and does not want to get involved. This can be done for two reasons: it can be done because a country does not want to get drawn into a dangerous situation or it can be done because the head executive may believe there is a benefit to not having trade agreements or mutual pacts with another country.