“Day Zero” is a time capsule from a parallel universe I thought we’d enter seven years ago — a universe where the draft is reinstated. Three friends struggle with the fast-approaching deadline with varying expressions of frustration and acceptance.

Elijah Wood, a self-loathing novelist, buys a Bowflex and pitifully attempts a few drill sergeant-soldier exchanges in front of the mirror. Chris Klein, a pampered lawyer, Googles “conscientious objector.” He drinks a bottle of rosé in his Architectural Digest bathroom trying to work up the courage to hack off his trigger finger with a glistening santoku. Jon Bernthal, a television actor, holds his own completely with Wood and Klein as the Economist-reading taxi driver who says it’s worth fighting for freedom — even if it is just freedom to be screw-ups.

It works because each of them know how pitiful they look. (The only off performance came from Ally Sheedy, Wood’s sinister, crossword-completing, Valley girl sighing shrink. Sheedy appears to have thought she was appearing in a “Saturday Night Live” sketch.)

“Day Zero” is unadorned truth, but avoids being preachy or bloodless. Director Bryan Gunnar Cole’s time as a documentary director couldn’t have been used better — and I hope writer Robert Malkani (a former i-banker) keeps up the stories. They know, like Orson Welles said, “The enemy of art is the absence of limitations.” You don’t need more than a cast of six, the empty brackets of the Manhattan skyline between 40 Wall Street and the Woolworth Building, an occasional NPR-like radio drone of explosions and death and a script that sounds transcribed instead of labored over by sitcom writers.

Many people have considered what would happen if the draft were reinstated. I wrote a column extending the invitation on a car-ride to Canada in 2001. But as “Day Zero” shows, the draft would have at least one positive and immediate effect: Destroying the unfortunate world where you don’t have to consider the war at all.