On Jan. 28, Page 1 of The Times' business section carried a photo of picketing steel workers, carrying signs bearing the number of their local and the words, "Locked Out."
Because the picture was so clear, I am forced to wonder whether your caption writer looked at it before writing the caption, which reads: "Among its other woes, USX has been hit by a six-month strike."
For the benefit of your caption writer, a lockout occurs when a company locks its doors and stops production for its own reasons, even when workers are willing to work. A strike occurs when workers withhold their labor from their employer in an effort to obtain better wages and/or working conditions.
The "labor dispute" at USX was, as the picketers in the picture indicate, a lockout, not a strike. When the contract between USX and the United Steelworkers expired six months ago, the Steelworkers were willing to continue working under the terms of the old contract, but USX refused the offer.