That was the question Pew Research asked pollsters regarding how to handle immigrants who are living in the United States illegally. The results: 7 in 10 said undocumented immigrants should be able to stay legally while 27 percent said they should leave.

LONDON — At the Bestco International supermarket on central Edgware Road, British customers can stock up on staples of Twinings tea and HP sauce. Muslims can buy freshly butchered halal chicken, while homesick Poles can buy distinctly non-halal pork kielbasa imported from Silesia. The store is typical for catering to the various nationalities that have recently flocked here. Unscientific as it is, the snapshot reflects a more detailed picture that emerged last month when the government published the results of its first census in a decad.

MOSCOW — There was a Congolese man, stabbed on the Moscow metro. And a Muslim girl, beaten with a bat by three teenage boys, who told her to get out of their northern Russian city, Kondopog. But perhaps the most disturbing recent example of racial violence was the murder of Muslim activist Metin Mekhtiyev, who was knifed in the neck and face outside his building in central Moscow earlier this month. Xenophobia toward non-whites is rising in Russia, especially toward migrant workers from Central Asia and the restive North Caucasus region, where unemployment is rampant.