For the purposes of this discussion we will have the Port Moresby invasion forces and their primary escort and support forces remain intact during the Battle of the Coral Sea. This means that the Shoho is not lost ( say the report on the morning of May 7th from the Yorktown scout plane is accurately received as cruisers and not carriers and the strike is not launched). The main US and Japanese carrier forces then proceed to manoeuver and attack each other more or less as they did IOTL resulting in both forces pulling out after inflicting the same amount of damage to each other.
Meanwhile Admiral Abe, with his force fully intact and not getting cold feet with the battle raging behind him, orders his forces to proceed. The question then. Is there enough Allied strength at this tiime in and around Port Moresby to stop the invasion.
Can the defenders prevent the Japanese from getting ashore? If a beachhead is established can they contain it? And if they cannot hold the Japanese back and the city falls, would it be possible for the surviving allied forces to get to an alternate defensive position and enable them to continue contesting New Guinea. Or is it all game over for the Allies.
And now the other big question. How does this impact the course of the Pacific War. In the case of a less than complete victory by either side, the key to gaining that final triumph ia going to be how fast each side can reinforce which would inevitably mean a significant commitment of resources. Would this be enough to abort the Midway operation? Maybe if the US decides to commit its remaining carrier strength which may in turn have Yamamoto decide the Coral Sea will be the place for THE decisive battle. Thoughts ?