From the very beginning, Sweden was at war with its neighbors. By the 1800s, the years of conflict had drained the country, making it one of the poorest in Europe. Millions of people fled from the nation. In the mid-1600s and then again between 1840 to 1920, two waves of Swedish emigrants headed for North America, which explains the strong ties between Sweden and the United States that still exists today. It also may help explain why American visitors won't encounter a language barrier.
Most Swedes speak English.
In the latter part of the 19th century, Sweden declared neutrality. It hasn't been involved in a war since 1814. Apparently pacifism was a wiser path. Sweden now enjoys one of the highest standards of living in the world. The weather is actually pretty mild year-round due to the persistent warmth of the Gulf Stream.