Depends on the panic levels. Here's a rundown:

> If panic levels will go to yellow or below (up to 3) on all continents involved, leave it.
> If panic levels will go to orange (4) and the difficulty is easy or medium, take the mission. If the difficulty is hard, it's probably not worth it.
> If panic levels will go to red (5), then take it no matter what the difficulty.

Obviously, prioritise the place with highest panic. Finally, some advice - don't rely on a single team! Make sure you have spares.