Sorry, but your submission has been removed because we don't allow hypothetical questions. If possible, please feel free to rephrase the question so that it does not call for such speculation, and resubmit Otherwise, this sort of thing is better suited for /r/HistoryWhatIf.

Absolutely Unlikely. It's true, one of the major goals of the conspirators was to reach a truce with the Western allies to concentrate on successfully concluding the campaing in the East. In fact, one of the major motivating factors for officers to join the conspiracy was disagreement with the way the leadership and Hitler handled the Eastern Front militarily. They thought that with Hitler and his lackeys out of the way, they could still reach a favourable outcome there.

So a truce with all of the Allies was never really on the table, which already created a big problem. They believed that the Western Allies saw the Soviet Union as the natural enemy of all of Europe as they themselves did, and they never really seemed to understand that the western Allies had a rather positive attitude towards the Soviet Union, and weren't as critical of an advancement of the Soviets towards Central Europe as they later were. There were several attempts to reach out to the western Allies, for example via the Dutch Resistance, and while the Dutch favoured cooperation with the Germans, the British, for example (and not unreasonably) saw a categorical difference between resistance in occupied territories and the conspirators inside of Germany.

There's a twofold dilemma here: On the one hand, for the German resistance saw themselves as 'allies' of the Allies in the fight against Hitler, on the other hand they were trying to form an alternate government for the main enemy of the Allies. And for the Allies, the German resistance was simply a group operating inside of the main enemy, whose success wouldn't really change something about Germany's European hegemony aspirations. And ending this problem, and destroying Prussian militarism, was one of the major war goals particularly of Great Britain. It didn't help in that regard that so many members of the resistance came from the nobility and traditional (often prussian) military families.

One could say that the German resistance became a victim of international conflicts and power constellations. A simple change of government in Germany was desired by no-one but the conspirators themselves. After Casablanca, nothing but an unconditional surrender would do, and that was nothing that the conspirators would accept.

Very unlikely.

After the the Casablanca conference of January 1943 the Allies had promulgated the 'Casablanca Doctrine' that the fight against the Axis powers would continue until their unconditional surrender. Whilst Churchill coined the phrase in the World War II context (after U. S. Grant's statement in the American Civil War), he was personally somewhat amenable to a conditional surrender of the Germans that would maintain their ability to resist Soviet Aggression in the post-war period.

However this was, by July 1944, not going to happen, the build-up of US forces and logistics for the invasion of Europe had increasingly placed Churchill as the least powerful player of the 'Big Three'; Roosevelt, Churchill and Stalin, and it did not serve the interests of either the Soviets or the Americans to make an accord with a new German regime in the event of Hitler's death. In the case of Stalin, this was due to not having secured the 'buffer' territory he thought the Soviet Union required in Eastern Europe, and Roosevelt felt it important that a situation reminiscent of the end of the First World War, with Germany able to claim that it had not been defeated and the revanchism this inspired, a future possibility.

The Stauffenberg plotters would have has to surrender unconditionally, and this would have saved millions of lives, but if they continued to resist in the hopes of better terms, the result would have been much the same as if the Nazis had remained in power.