In the middle of an increasingly tense exchange with an African-American neighbor, a white home buyer in “Clybourne Park’’ says to her: “It’s . . . it’s race, isn’t it?’’

Yes, it is. Whatever the ostensible topic of conversation — and circuitous small talk certainly abounds in Bruce Norris’s Pulitzer- and Tony-winning drama — the true subject is almost always race. And in M. Bevin O’Gara’s sharp and penetrating production of “Clybourne Park’’ at SpeakEasy Stage Company, the fuse is always lit. The only question is when the explosion will come.