The opinion
WOOD, Circuit Judge,
concurring in the judgment.
The Union may not realize it upon its first reading of the majority’s opinion, but it has in fact won the war even if it lost the battle over what happened at Jones Plastic and Engineering Company (the Company). My concern over the majority’s opinion is that portions of it might be read to endorse more of the Board’s legal approach in this case than I believe it actually has done. I thus write to summarize what I believe we are holding, and why I am concurring in the ultimate judgment to deny the Union’s petition for review.
The question before the Board, succinctly put, was whether the workers that Jones Plastic hired during the Union’s economic strike were permanent or temporary. If they were permanent, then under well-established rules, the Company was under no obligation to release them when the Union made its unconditional offer to return the striking employees to work. See NLRB v. Mackay Radio & Tel. Co., 304 U.S. 333, 345-46 , 58 S.Ct. 904 , 82 L.Ed. 1381 (1938). If the replacements were temporary, then the employer cannot demonstrate the “legitimate and substantial business justifications” for refusing to reinstate the strikers that is necessary to avoid a finding of an unfair labor practice. See NLRB v. Fleetwood Trailer Co., 389 U.S. 375, 378 , 88 S.Ct. 543 , 19 L.Ed.2d 614 (1967), quoting NLRB v. Great Dane Trailers, 388 U.S. 26, 34 , 87 S.Ct. 1792 , 18 L.Ed.2d 1027 (1967). In this ease, the Board had to decide how to apply these rules to a reinstatement offer that promised only employment at will and that emphasized that the replacement’s “employment with Jones Plastic may be terminated by [the replacement] or by Jones Plastic at any time, with or without cause.” See ante, at 845.
Both the Union and the two dissenting members of the Board are concerned that an offer like this one erases the distinction between a permanent and a temporary replacement. As the dissenters put it, the Jones Plastic offer “created a situation in which ‘the replacement could be fired at the will of the employer for any reason; *861 the employer would violate no promise made to a replacement if it discharged some of them to make way for returning strikers.’ ” Jones Plastic & Eng’g Co. & United Steel Workers, 351 NLRB No. 11 , at *10 (Sept. 27, 2007). The Union argues that such open-ended discretion on the part of the Company would allow it to discharge just enough replacement workers to create job openings for striking workers who had become disenchanted with the Union or who promised to oppose further unionization efforts. It points out that the classic definition of employment “at will” is an arrangement under which “absent express agreement to the contrary, either employer or employee may terminate their relationship at any time, for any reason.... Such employment relationship is one which has no specific duration, and such a relationship may be terminated at will by either the employer or the employee, for or without cause.” See Black’s Law Dictionary at 525 (6th ed.1990). Although there are some narrow limitations on the employer’s discretion— for example, Illinois recognizes an exception for cases in which an at-will employee is fired because he reported dangerous or illegal activities at work, see Robinson v. Alter Barge Line, Inc., 513 F.3d 668, 671 (7th Cir.2008), and at-will employees may state claims for racial discrimination in employment under 42 U.S.C. § 1981 , see Walker v. Abbott Laboratories, 340 F.3d 471, 476 (7th Cir.2003) — this case presents the question whether a company is entitled to exercise its discretion to fire an at-will employee solely because it wants to bring back strikers in the absence of a formal settlement or order from the Board. In my view, the majority has answered that question “no,” for the reasons I outline below.
First, the majority reaffirms the rule that the burden of proving that a replacement worker is permanent lies on the employer. Ante, at 851. Second, it accepts the Board’s “totality of the circumstances” approach to the determination whether a position is permanent or temporary. Ante, at 851. Third, just as both the majority and dissenting members of the Board did, the majority holds that it is possible for an at-will employee to be a permanent replacement: under all the circumstances, some will be, and some will not be. Finally, and critically, the majority rules that:
[T]he Board consistently has allowed employers to hire permanent employees while concomitantly imposing certain conditions on their retention, so long as there is a mutual understanding that the employer’s desire to reinstate a striker will not cause the replacement employee’s discharge.
Ante, at 855 (emphasis added). The language in italics is conceptually identical to the rule for which the Union argued here. As the majority notes, ante, at 849 n. 1, the Union took the position that the following language would address its concerns:
I understand that my employment with [the employer] may be terminated by myself or [the employer], at any time, with or without cause, for any reason other than to permit the return of a striker unless the return of such striker is required by a strike settlement agreement reached between [the employer] and [the union] or by order of the [NLRB].
The Board majority rejected the Union’s solution, saying that it was not prepared to require “specific language” of any type. In my view, that is not what the Union was requesting; it was saying only that the idea conveyed in the language it suggested had to be communicated to the replacement workers, and it was offering one verbal formulation that would do the job. The majority is willing to accept the *862 Board’s argument that the Union’s suggestion was “too complicated,” ante at 847 and 849, but I do not. No matter — as the Board itself recognized, the precise language is not the point: it is the concept that must be communicated to the replacement worker. The majority suggests that “[o]ne possible interpretation of [the Jones Plastic form] is that the statement of permanence contained in this form is an exception to the at-will language and therefore creates an enforceable contract that Jones Plastic will not discharge the replacement employee in favor of a returning striker.” Ante, at 857 n. 8. I agree with them that this is “one possible interpretation.” Moreover, reading the majority’s opinion as a whole, I conclude that it is the necessary interpretation. That is the only approach that is consistent with the majority’s observation that “[u]nder [the] totality-of-the circumstances approach, Jones Plastic could not have fired some of the replacements in favor of some of the strikers while denying reinstatement to the remainder of the strikers on the ground that the replacements were permanent.” Ante, at 856.
In the end, therefore, the majority has placed an important gloss on the decision of the Board majority. That gloss is exactly what the Union requested, as a matter of law. Before a replacement worker who was hired as an employee at will can be characterized as “permanent,” and thus before an employer may refuse to release the worker when the economic strikers make an unconditional offer to return to work, the company must somehow make it clear that the employer’s normal discretion to fire the at-will replacement employee is constrained: it may not fire the at-will worker just to create a position for a returning striker, unless that action is required either by a strike settlement agreement or by an order of the Board.
All that remains is the question how to apply these rules. The majority rightly notes that the court must defer to the Board’s factual determinations. One of those determinations is the question whether, under the totality of the circumstances, the Jones Plastic replacement workers were permanent or temporary. The Board majority’s opinion does not spell out the limitations on the employer’s discretion with respect to at-will employees as well as the majority’s opinion does. But, on these facts and bearing in mind the applicable standard of review, it is possible to find that the Company satisfied its burden of proof. I therefore concur in the judgment.