Does the US secret service share information with other countries?
The main ones are 'Secret' and 'Service', usually utilized in that order.
How does FBI connect to other secret service agencies?
They use an MTAC (Major Threat Assessment Center) - A Vidieo conference Suite
Why does the US not want anything to do with other countries?
if you're talking about after 9/11then people disrespect Muslims alot and they don't show any kindness toward them but some do