STOCKHOLM, Sweden — Until a few weeks ago, Egor Putilov was a parliamentary aide for the far-right Sweden Democrats Party and a well-known anti-immigrant newspaper columnist who regularly blasted the government for granting asylum to Middle Eastern refugees.“If nothing is done, Sweden’s lax immigration checks could prove very costly,” Mr. Putilov wrote last year in an op-ed for the Aftonbladet daily newspaper, ominously suggesting that Islamic State terrorists were slipping across Sweden’s supposedly porous borders.
