What if a South American state gained nuclear weapons?

How would the doctrine change if a South American nation developed nuclear weapons during the Cold War?

It would challenge American assumptions of hemispheric leadership. The comparison with naval competition suggests pressure to respond, without specifying a nuclear-policy response.

A hypothetical South American nuclear arsenal during the Cold War would challenge the United States' assumed military leadership in the hemisphere. The comparison is with earlier South American naval programmes that rivaled American strength. A second counterfactual asks how Washington would react if Canada acquired Queen Elizabeth-class battleships. Increased American naval investment is the suggested response to that battleship scenario; the nuclear scenario receives no detailed policy forecast.