The import of those passages you quoted there Keith were not that there was "no choice", but that the writer believed that the right choice was made. And the arguments for that are based on imagining what the outcome of different choices might have been.

Essentially it boils down to "This is what happened. These are the decisions which were made. These are the things that happened as a result of those decisions. The consequences were disastrous, and the subsequent consequences have also been disastrous. But I believe that if different decisions had been made the outcome would have been even worse."

The last sentence is not actually history, but speculation by a historian. Making up alternative paths in history is an interesting thing to do, but history academics have no special or unique aptitude for doing it.