"The essential qualities of a true Pan-Americanism", remarked Franklin Roosevelt in 1933, "must be the same as those which constitute a good neighbour, namely mutual understanding and... a sympathetic appreciation of the other"s point of view." That is advice which the United States would do well to heed in its relations with its immediate neighbours, Canada and Mexico. Most Americans may not be aware of it, but frustrations and resentments are building just across their borders to both south and north. Of course, neighbourly ties in North America are closer than in Roosevelt"s day. Under the North American Free-Trade Agreement (NAFTA), trade among the three countries has more than doubled since 1994 and cross-border investment climbed even faster. In the aftermath of the terrorist attacks of September 11th 2001, the United States moved quickly to sign "smart border" agreements with both Canada and Mexico, to try to ensure that the demands of security did not interrupt trade. By the standards of much of the 20th century, political ties between the United States and Mexico are warm. Yet go to either border and you wouldn"t know all this. Fed up with the flow of illegal migrants from the south, the governors of Arizona and New Mexico this month declared a state of emergency. Violence between drug gangs recently led the United States temporarily to close its consulate in Nuevo Laredo, the busiest border-crossing point. The American ambassador bluntly criticises Mexico for its failure to prevent drug-related violence along the border. That has prompted retaliatory verbal blasts from Mexican officials. Canada"s mood is not much more cordial. Since September 11th, Canadians and Americans alike have become less keen on popping over what they liked to call "the world"s longest undefended border" for shopping or recreation. Canadians increasingly disagree with Americans over matters as varied as the Iraq war and gay marriage. They are disillusioned with NAFTA, claiming it has failed to prevent the United States from unlawfully punishing their exports of, for example, lumber. So what Friction is in the nature of international relations, and the problems on the northern border are different from those in the south. Yet there is a common denominator. Americans tend to see security, migration, drugs, even trade, as domestic political issues. But so they are for Canada and Mexico too. Like it or not, Americans rely on their neighbours for prosperity, energy and help with security. It behooves all three countries to show some "sympathetic understanding".It can be inferred from the first paragraph that ______.