Complex sentence: Robinson supported the plan and confirmed with Treacy that they would not request permission from GHQ, if they did they would be obliged to wait for a response and even if the response was affirmative it may come back after the gelignite was moved.
Split into simpler sentences: Robinson supported the plan and confirmed with Treacy that they would not request permission from GHQ. If they did, they would be obliged to wait for a response, and even if the response was affirmative, it might come back after the gelignite was moved.