Yes. If you are a US Citizen, you need a passport to travel anywhere outside the USA. This typically applies to all other nations as well.
only if you are going to Northern Ireland, you need a passport to travel between England and Ireland.
No, Belfast is in Northern Ireland which is part of the UK - you don't need a passport to travel from one part of the country to another.
no - it's an internal UK ferry trip
Yes, you need a passport to travel to Europe.
Yes, you need a passport to travel to Paris.
You need a passport
Yes they do need a passport for Northern Ireland
No, you do not need a passport to travel to Arizona if you are a U.S. citizen.
Yes, you need a valid passport to travel to Brazil.
Yes, you need a valid passport to travel to Colombia.
Yes, you need a valid passport to travel to Peru.
Yes, newborns need a passport to travel internationally.