"One of the bylaws of the International Association of Time Travelers states that you can't kill Hitler. The problem is, everybody kills Hitler on their first trip. This leaves more experienced time travelers the onerous task of undoing the historical edits of n00bs."<p><a href="http://www.tor.com/stories/2011/08/wikihistory" rel="nofollow">http://www.tor.com/stories/2011/08/wikihistory</a>
As always, tvtropes already has the answer:<p><a href="http://tvtropes.org/pmwiki/pmwiki.php/Main/HitlersTimeTravelExemptionAct" rel="nofollow">http://tvtropes.org/pmwiki/pmwiki.php/Main/HitlersTimeTravel...</a><p>See also:<p><a href="http://tvtropes.org/pmwiki/pmwiki.php/Main/TimeTravelTropes" rel="nofollow">http://tvtropes.org/pmwiki/pmwiki.php/Main/TimeTravelTropes</a><p>Warning:<p><a href="http://tvtropes.org/pmwiki/pmwiki.php/Main/TVTropesWillRuinYourLife" rel="nofollow">http://tvtropes.org/pmwiki/pmwiki.php/Main/TVTropesWillRuinY...</a>
If you subscribe to the multi-verse theory, then you can. Except when you "return" to your own time, you are forced to travel to a present where you did kill Hitler. Your own original time, where you didn't hill Hitler continues on as it was except you can no longer travel there.<p>Killer Hitler is like throwing a railroad switch and changing tracks, once entropy send you down the new track, there's no hopping back across. And even if you <i>could</i> you'd just be going to a present time where you failed to kill Hitler.
The true reason is probably much simpler than any of those considering war has a profound impact wherever it strikes. WW1&2 were triggered by a long chain of events and itself sparked another chain of ongoing events, affecting great many lives dead or not (including myself). If it all possible, you may have to mate with an ancestor to get your own life back.
On a slight tangent, this story sent me off researching the alleged German time-manipulation project ( Die Glocke ) which led to a report about Mr Hitler's last surviving bodyguard, who died last week:<p><a href="http://www.bbc.co.uk/news/world-europe-23989454" rel="nofollow">http://www.bbc.co.uk/news/world-europe-23989454</a>
I hate explanations like "you can't change history". It's a self-fulfilling prophecy. You don't kill Hitler because you didn't kill Hitler.
This whole issue leads to a dark place (intellectually). Would you be alive today without WW2 or without the Holocaust?<p>I wouldn't. How am I supposed to feel about that?