Trump's rise sparks isolationist worries abroad, but voters unfazed

As Donald Trump strengthens his lead in the race for the Republican presidential nomination, some U.S. allies are worried about an American turn toward isolationism, a shift that would reflect an electorate largely focused on domestic issues.

That was shown in polling in Iowa where Trump scored an overwhelming victory on Monday, with foreign policy the top issue for just one in 10 participants in the state's caucus, according to a poll by Edison Research.

That compared to four in 10 who said the economy was No. 1 and three in 10 who pointed to immigration.

National polling provides a similar picture. When Americans have cited matters involving foreigners as the country's top problem, they most often have referred to immigration and not foreign conflicts, Reuters/Ipsos polling over the last decade shows.

In a December Reuters/Ipsos poll, 6% of respondents nationwide said war and foreign conflicts were the U.S.'s most pressing problem, compared to 11% who cited immigration and 19% who pointed to the economy. Ten percent cited crime.