You remember back, that moment you smiled to yourself as you flipped through the time portal, sure you broke all the rules but you did it, you killed Hitler! You were a hero in your own mind, you finally put the age old theory into practice, sure you killed a kid, but it was Hitler! As you flipped back into existence where the great time portal stood you found yourself stood opposite the burnt out wreckage of a building. Since that day you'd tried to unravel what had happened.
The Nazi party never took over power and there was no great conflict of Fascists versus the world. It appears that the Japanese conquered most of China and Asia Pacific their borders pressed against that of the fracturing British Empire in India and the Soviet Union in the North. The Soviet Union had amassed a vast military manufacturing base. The Germans fought a Guerrilla war against the French in the Rheinland aided by the British. The Spanish civil war rumbled on between nationalists and communists. The United States maintained its Isolationist policies in regards to world affairs and maintained strong trade relations wherever possible.
It appears the Americans didn't feel an existential threat in the face of the Soviet Union given that no dominoes had fallen, though it kept a close eye on the Japanese that seemed to continually operate in the south pacific and the British who were far too fond at meddling in other people's affairs. The British held tight to its empire and continued to prosper at the expense of its subjects India was beginning to prove difficult. In 1952 the Russians launched an invasion of Europe, they'd conquered all of Germany before the summer, France was wholly unprepared while the British looked on stunned. Americans had no appetite to get involved in the European medley and so kept to themselves selling arms and manufacturing facilities to any who could afford it.
France fell quickly and the whole of continental Europe "joined" the European Soviet Collective, puppet governments were set in place and secret police were commissioned, the British pulled a number of warships from the pacific to ensure Russians couldn't get across the channel. Next, the Japanese launched attacks on the British Pacific assets supported by Indian patriots. You'd found some reports that Japanese operations in China and Korea had cost some 50 million Chinese lives. The Soviets had stayed on track with about 20 million of their own people before the conflicts begun.
The British Empire was against the wall and decided to deploy the ultimate weapon, it dropped a number of nuclear weapons on Russian forces in Europe. Russia had also developed the bomb and bombed a number of British cities. Japan launched an attack on America by turning Pearl Harbour, Midway and LA into glass parking lots. After twenty years of global conflict, it seems most sides just broke down and were no longer able to prosecute combat anymore.
All in all, it turned out Hitler wasn't the worst that could happen.