The Austral War is an invasion from an extra-dimensional race.
RPC-998 is an invasion from an extra-dimenstional race.
I would replace the Austral war with RPC-998's story. It takes place in the 50s, so not too distant from the Austral war in the 40s. Plus having the war be after WW2 makes the Authority having nukes and a large military force more convincing. Also having the Authority be directly involved in BOTH world wars is too big of a coincidence for me. WW1 directly led to WW2, so even without direct intervention, the Authority would still have caused both.
"30 November 1954: An experimental Authority spacecraft succeeds in destroying a hostile Unidentified Flying Object over northeastern Alabama."
Instead of killing it with a spaceship, there could be a big battle where a large airborne TRT using retired WW2 planes is required to take it down. This could make the Authority realize space assets are crititcal to its mission. After some cost analysis it is determined that the Authority doesn't have the resources to fund a space program. So, they could convince the US and USSR that putting people on the moon would help them win the cold war. Then the Authority could take the technology they develop. That way they have a space program without spending billions of dollars for inital research.
During the space race most the technology we use in space today was developed. Reuseable heavy lift rockets. Nuclear engines. Life support. Space stations. Space construction machines. The reason we don't see any of these being used today is because the cold war ended, but the Authortiy has continued to use them for the past 50 years. As a result the Authority has a comprehensive network of Areas, ships, and satalies in space today.
(account deleted)