The question asked at first glance sounds ludicrous. Germany quite clearly was defeated in WW1 and WW2. The sense of the question comes clearer, however, when you look at who Germany’s enemies were. If the US had not intervened in both wars, it is probable that Germany would have won on both occasions. But who are the Americans?
Not very often mentioned is that Germans make up the largest ethnic group in the USA, with 50 million Americans in 2006 claiming German descent. They were the biggest nationality of immigrants into the US, and while only some of these made it to President such as Nixon and Hoover (anglicised from Huber), Americans of German descent have been at the forefront of many aspects of American life, and particularly of all American military victories starting with the War Of Independence against England.
Baron Von Steuben, a Prussian officer is credited with having reorganised the American Army and worked out the tactics that turned probable defeat by Britain into victory for the colonists.
In the First World War it was General Pershing, a name of German descent, who commanded America’s forces on the western front. In WW2 it was Eisenhower (from Eisenhauer), and more recently in the first Iraq War it was Schwartzkopf who delivered victory to his President.
In the First World War anti-German feeling had been strong in the US, and many anglicised their names. Wikipedia reports as follows –
Several thousand vocal opponents of the war were imprisoned.
Thousands were forced to buy war bonds to show their loyalty. The Red Cross barred individuals with German last names from joining in fear of sabotage.
One man was hanged in Illinois, apparently for no other reason than that he appeared to be of German descent. The killers were found innocent of the crime and the hanging was called an act of patriotism by a jury. A Minnesota minister was tarred and feathered when he was overheard praying in German with a dying woman. Some Germans during this time “Americanized” their names (e.g. Schmidt to Smith, Müller to Miller, Rickenbacher to Rickenbacker, Eisenhauer to Eisenhower) and limited their use of the German language in public places.
In the second world war, Roosevelt’s top commanders were of German descent. Again Wikipedia recounts the list –
President Franklin D. Roosevelt did not hesitate to name Americans of German ancestry to top war jobs, including General Dwight D. Eisenhower, Admiral Chester Nimitz, and General Carl Spaatz. He appointed Republican Wendell Willkie as a personal representative.
German Americans who had fluent German language skills were an important asset to wartime intelligence, and they served as translators and as spies for the United States. The war evoked strong patriotic sentiments among German Americans, few of whom by then had contacts with distant relatives in the old country.
It seems as if I’ve answered the question. Germans did win both world wars. Interestingly George Bush has done better in Iraq since he appointed a General of German descent in Petraeus.
The Cold War too was greatly assisted when America adopted Von Braun’s scientific team from Peeenmunde, giving the US the edge over the USSR in rocketry.