Over the course of millennia, some of the people of Earth have been transported to entirely new worlds. Over time, they reestablish civilizations, expand, grow culturally and scientifically, and eventually discover ways of reaching the other planets their fellow humans have washed upon.
However, their ability to contact other planets raises one important point: Might it be possible to 'go back home'? Historical artifacts and memory generally prove that these people did not originate from the world they came from, so could they rediscover their 'homeland' and return to it.
My current answer is yes, it is physically possible for transport and communication between these outside worlds and Earth. However, I haven't figured out just how these other humans would go about doing it. Those on Earth aren't aware of their existence, bar a small number who these outsiders could use to establish communications.
In all, my question is: How would a nation/political entity as advanced as our own go carry out the process of initiating communication with the nations and people of Earth.
Some things about to note:
- They are only able to send a small delegation to Earth public
- There are some groups on Earth who are aware of them, and who wish to keep them secret from the rest of Earth, due to their ability to use magic
- They are able to communicate verbally and through written words with Earth humans
Edit: I am not asking about the science of the matter, but about the politics, or the actions that a government would take when initiating contact.