The transistor was never discovered. Following the events of WW2, countries turned to science as an answer to ensure such horrors would never repeat themselves. And how the discovery of microfusion and advanced nuclear physics helped the world flourish: by 2040, nearly every household in the First World had a spanking new Mr. Handy robot for performing simple tasks, fission batteries and fusion cores the size of baseballs powered machinery, and nuclear power seemed to reign in the future.
Alas, war never changes. Fossil fuels never did become obsolete, and by 2054 the world was in chaos. As the Middle East and Europe went to war over the precious fuel reserves that remained, with virtually every capital city in the region razed, annexed or evacuated within 2 years, the Americas and Asia looked on.
Having escaped the Resource Wars, Asia and the Americas looked into their borders for oil, and found supplies inadequate. China was the first to act, invading Alaska in 2066 for the rigs there. Mexico and Canada became absorbed into the United States, acting as buffers from the oil-hungry Latin America and China. Latin America never look out of its continent, consuming itself in war as its states fought for territory. In a costly retaliation, the United States equipped its soldiers with cutting edge technology and sent them first to liberate Alaska, then topple Beijing. This would largely prove successful, American boots crossing Yangtze in 2066. The two powers would not remain idle.
In 2077, nuclear fire consumed the earth.