Yes, with a caveat worth being honest about. One English language site can rank in the United States, Canada, the United Kingdom, Australia, New Zealand and Ireland at the same time, because Google serves the same index with regional weighting. What a single site cannot do is win local map results in a country where you have no address and no local phone number. If you sell a service remotely, one strong site is the right answer. If you need to appear in the map pack in three countries, you need a registered presence in each, and I will tell you that before you spend anything.