It is said that there is wisdom in the nations. Chassidus teaches that Jews have more vessel and less light, and non-Jews have less vessel and more light. There seems to be a possible good that comes out of forming friendships with non-Jews. But the general attitude seems to be not to be friends. Barring the prohibition to drink together, shouldn’t Jews socialise and be friendbefriend gentiles more? Wouldn’t it be part of darkei shalom?