Here's something based on an old scenario by Tormsen, another alternatehistory.com stalwart.
In this world, a different Kaiser without a fetish for battleships, and a rightward swing in British politics (see: "Fight and be Right" at alternatehistory.com), combine to the point where WWI is fought as a British-German-Austrian-Italian alliance vs a French-Russian-Serbian one, and the Brits and the Germans carve up the spoils. With new and extensive commitments, social unrest and Leftist violence, and efforts by the losers to reverse their losses, the peace is an uneasy one, and the dominant classes in England and Germany shift further to the radical right. Racist, "Aryanist" ideas about the fundamental superiority of the Germanic peoples, whether Deutsch or Anglo-Saxon gain in popularity.
Worried about these developments, the US, Japan and a shrunken Russia form a defensive alliance: some decades later, Some Damned Fool Thing in China boils over, and the Two Oceans (Pacific and Atlantic) war kicks off. The US does well at first, and overruns Canada: but the German-British nuclear project bears fruit first, and in the end the US and its allies are smashed. Canada, with British backing, takes a hearty revenge on the US and gets the job of kicking them if they seem to be getting back up.
Another consequence of the war is the rise of India: uncertainties as to whether the often dark-skinned northern Indians were really "Aryans" were resolved by the need to build up and industrialize India, lest Britain end as a junior partner to the Germans. North Indian elites, Hindu and Muslim, were co-opted, Indian nobles married spare British dutchesses, and an Indian-British "Aryan" partnership discussed. The Two Oceans war provided the opportunity for India to become essentially independent within the Empire, self-rule in exchange for full military cooperation...
Some thirty years later, the Brits are feeling down in the mouth: not only have Canada, South Africa, and Australia become near-independent and generally only listen to London when it pleases them, but India in 1972 out and out rejected Dominion status, although maintaining "friendly ties" - Indians now consider themselves equal partners with the British, and have taken over the running of much of the vast informal and puppet empire of Britain in Asia and even Africa, having far greater cheap manpower. Problematic non-Indoeuropean south India has been spun off as a puppet state, while Iranic Afgans, Tajiks, etc. have been absorbed. (So has non-Aryan Tibet, but Tibet has Mythic Significance in this world's Aryan cultism, as it did in our world). The state is secular and racially based, so Muslims and Hindus are at no disadvantage to eachother, while darker-skinned southerners are in trouble, and the Caste system, supposedly originally racial, has if anything been strengthened. Having followed a more capitalist economic path and recieved more British industrial investment, India is relatively a lot wealthier than OTL 1976, about where China was in the early-to-mid 1990s.
The US was put under a severe arms limitation and forced to pay massive reparations, but the US managed to pay off the second within a decade and soon found ways to avoid the first: secret agreements were made with Brazil and other members of the League of the Americas (a shaky Latin American alliance put together to form a common front against German and British pressures) and the backwoods of South America served the US as the USSR's interior served Germany our timeline in the 1920s. By 1976 several Latin American nations had substantial "native" high-tech arms industries, and Brazil, Argentina, and Mexico had "self-developed" atomic weapons. Under German and British threat, the US has no atomic power industry: but it is estimated by German and British intelligence that the US now has enough smuggled-in nuclear weapons in the country to achieve MAD with Canada, and is pushing hard against other military restrictions by various means. Canada has cut back on its overflights of the northern US, fearing to provoke an incident.
The League of the Americas, with heavy US investment and a big free trade zone, has become a rather more muscular animal, although with heavy use of carrot and stick the Germand and British have managed to peel off a few of its weaker members, and is generally richer and more democratic than Latin America OTL in 1976. The League has gained allies across the Atlantic: the Spanish Republic which replaced the Junta in the 60s has moved to align itself with its Latin brethren across the Ocean, and France has given independence to those few colonies it was left after the first war: League of the Americas support has prevented them from falling into the German or British orbit. (Alas, the French effort to develop its own nuke on the sly did not work so well, and the Germans have occupied the country again).
The German leadership, not having a hostage like Canada, are beginning to whisper about perhaps putting an end to the US for good - although this world has no ICBMS as yet , the Germans have enough trans-oceanic bombers to do the job - while the ability of the Americans to strike back is still limited.
On the one hand, multiracial America is a serious ideological challenge to the notion of Aryan superiority, and its continued democracy is poision to the "managed democracy" Germany has had since the Two Oceans war (where the military and the right-wing parties took advantage of wartime military dominance to launch an effective coup against the left-wing parties). The Reich is under pressure from a growing percentage of the population to open up the political system, and from the increasing costs of a multitude of inusurrections supported or at least cheered on by the League of the Americas.
On the other hand, a lot of Germans, including very conservatives ones, are strongly opposed to the notion of preemptive genocide vs the US, and then there is a great deal of uncertainty as to just how many long range bombers and nuclear-weapon carrying submarines the Americans might have...
The Chinese Republic, which received a terrible kicking in the last war, and still are forced to accept European laws prevailing over Chinese ones along the coast, are suffering from increast political turbulence and revolt in the interior, although a frail sort of prosperity has come to the big eastern cities where the cheap labor is exploited by German, British, and increasingly Indian companies. Japan, which never received the cushy trade terms it did OTL after WWII, and has lost control of much of its local industry to German multinationals, is only just now starting to boom economically, and remains a minor player.
The Habsburgs are kings and subordinate to Hohenzollern Emperors in Austria and Bohemia, but Emperors and co-equals in the Federal Empire of Greater Hungary. It's complex.
The British Empire is still powerful, but only barely united, and Arab oil is the only real advantage it holds over the other Powers. And in Britain, the Imperialist, Aryan-ist concensus is breaking down: there is a lot of sympathy for the Americans notions of national sovereignty and independence (if not for the racial equality thing), and increasingly the young are less than enthusiastic about taking on the White Man's Burden...
 Although the Brits and Germans are messing around with rockets, as are (on the quiet, in the Andes) the Americans.