Answer:
it was not effective
Explanation:
This ultimately depends on the author's intention when writing the story. By making this time jump the author is relying on the reader to piece together the events through the few pieces of information provided. This makes the reader think and arrive at the conclusion through their own investigative work, which can be rewarding and fun but at the same time can leave some readers confused. If the events were explained thoroughly and the flash-forward removed then all the readers would know exactly what happened and how the story arrived at the conclusion. Therefore, I would say no it was not effective, and that it would have been better to know the details of Sergei's decision.