It will result in a loss of power. Isolation is not a strengthening posture. You need allies to succeed over the long term. This looks like the beginning of the downfall of the United States from every measure.
But WW2 ended colonialism and 90s globalization spread industrialization worldwide, leaving us all in the slow roll of reverting to the mean now. At the end of which, the ancient civilizations of China and India, with nearly 3 billion people between them, will return to global dominance.