dissenting.
On September 14, 1968, just six days prior to the expiration of the collective-bargaining agreement then in force, the Union membership voted to strike. The strike began September 20. On September 21 the membership unanimously1 adopted a resolution that anyone aiding or abetting the company during the strike would be subject to a fine not exceeding $2,000. Each of the employees involved here voted for both of these resolutions *219and participated in the strike.2 Each was a member of the Union during the period in which the votes were taken and the strike began. Membership was voluntary, and persons who became members were free to resign at any time.3
In NLRB v. Allis-Chalmers Mjg. Co., 388 U. S. 175 (1967), this Court held that a union could enforce in a state court a fine levied against a strikebreaking member. The Court noted that, at the time §8 (b)(1) (A) was enacted, "provisions defining punishable conduct and the procedures for trial and appeal constituted part of the contract between member and union and that ‘[t]he courts’ role is but to enforce the contract.’ ” Id., at 182. The scope of § 8 (b)(1)(A) was confined to restraint or coercion visited upon union members in the course of organizational campaigns, id., at 186-188, or by arbitrary and undemocratic union leadership, id., at 188-189, or by coercion that prevented employees not in the bargaining *220unit from going to work, id., at 189 and n. 25. That section was not viewed as prohibiting “the imposition of fines on members who decline to honor an authorized strike and attempts to collect such fines.” Id., at 195. Finding, as a consequence, no restraint or coercion by the union on the employees’ § 7 rights, the Court sustained the union’s power to enforce the strikebreaking fines in state court.
Today the Court reaches an opposite result on the basis of two facts: “Neither the contract nor the Union’s constitution or bylaws contained any provision defining or limiting the circumstances under which a member could resign”; and the strikebreaking employees resigned before returning to work, thus effecting “a lawful dissolution of [the] union-member relation.” As to the first fact, I am not convinced that the presence of a provision in the union constitution, for example, should always make a difference with respect to the existence of an enforceable, voluntary obligation on the part of an employee to refrain from strikebreaking activity. In fact, it seems likely that the three factors of a member’s strike vote, his ratification of strikebreaking penalties, and his actual participation in the strike, would be far more reliable indicia of his obligation to the union and its members than the presence of boilerplate provisions in a union’s constitution. As to the second fact, while membership in the union may well have implications with respect to the union’s power over the resigned member, I am hard put to understand why this fact, alone, results in restraint or coercion under §8 (b)(1)(A), when the imposition of fines for similar conduct by members, and their enforcement in state courts, does not fall within that section’s prohibition. NLRB v. Allis-Chalmers Mfg. Co., supra. Are an employee’s § 7 rights any more at stake here than they are where, as in Allis-Chalmers, the *221employee engages in the same activity but stops short of resigning from the union?
I cannot join the Court’s opinion, which seems to me to exalt the formality of resignation over the substance of the various interests and national labor policies that are at stake here. Union activity, by its very nature, is group activity, and is grounded on the notion that strength can be garnered from unity, solidarity, and mutual commitment. This concept is of particular force during a strike, where the individual members of the union draw strength from the commitments of fellow members, and where the activities carried on by the union rest fundamentally on the mutual reliance that inheres in the “pact.” Similar mutual commitments arising from perhaps less compelling circumstances have been held to be legally enforceable. See 1A A. Corbin, Contracts § 198, pp. 210-212 (1963).
A union’s power to enforce these mutual commitments on behalf of its members is of particular importance during the course of a strike. “The economic strike against the employer is the ultimate weapon in labor’s arsenal for achieving agreement upon its terms, and ‘[t]he power to fine or expel strikebreakers is essential if the union is to be an effective bargaining agent ....’” 388 U. S., at 181. The 31 employees involved in this case, joined with their then-fellow members, voted to strike as well as to impose' sanctions on those who broke ranks,4 and participated in the strike. Their votes were voluntary and uncoerced. They had notice of the fines, and raised no objections,, perhaps feeling that the hardships that would befall them during the strike would be compensated by ultimate victory at the bargaining table. They *222did not attempt to bring the matter to the vote of the membership, a majority of which could have, and later did,5 terminate the strike.
I am not convinced that in the strike context, where paramount union and employee interests are at stake, union enforcement of this mutual obligation by reasonable fines “invades or frustrates an overriding policy of the labor laws.” Scofield v. NLRB, 394 U. S. 423, 429 (1969).6 The Court of Appeals concluded that § 7 of the Act, granting employees the right “to refrain from any or all” collective activities, including membership and participation in strikes, was not involved in this case. Emphasizing the meaning of the word “refrain,” the court concluded that “although § 7 gives an employee the right to refuse to undertake and involve himself in union activities, it does not necessarily give him the right to abandon these activities in midcourse once he has undertaken them voluntarily.” 446 F. 2d 369, 373. See H. R. Conf. Rep. No. 510, 80th Cong., 1st Sess., 39-40 (1947). I believe this notion expressed by the Court of Appeals is applicable in the limited context of the economic strike. In my view, the policy of § 7 would not be frustrated by a holding that an employee could, in the circumstances of this case, knowingly waive his § 7 right to resign from the union and to return to work *223without sanction.7 The mutual reliance of his fellow members who abide by the strike for which they have all voted outweighs, in the circumstances here presented, the admitted interests of the individual who resigns to return to work. He may still resign, and he may also return to work, but not without the prospect of having to pay a reasonable union fine for which he voted.
The employees who resigned have not asserted any changed circumstances or undue hardships that would justify their resignations and return to work. Nor do they claim that the fines imposed on them were unreasonable.8 Perhaps these matters could be asserted before the Board or in defense in the state court proceedings under prevailing state law. As these issues have not been argued in this case, they need not be resolved at this time.
I would affirm the decision below.
There is a mild discrepancy in the record as to whether the vote on the strikebreaking resolution was unanimous. In his first opinion, the trial examiner indicated that the vote was unanimous. (Pet. for Cert. 23a.) In a second opinion, the examiner indicated that there was one dissenting vote.
The parties stipulated before the trial examiner that all 31 employees participated in the strike vote, and voted in favor of the strike. App. 45. It is less clear whether each of the employees voted in favor of the fine. These are matters that would be resolved in the state court proceedings.
The Union and the company had no union shop clause in the 1965 collective-bargaining agreement. The Union constitution and bylaws contained no express provision limiting members' rights to resign. In the absence of such a provision, the members could submit voluntary resignations at any time. NLRB v. Mechanical & Allied Production Workers, Local 444, 427 F. 2d 883 (CA1 1970); Communications Workers v. NLRB, 215 F. 2d 835, 838-839 (CA2 1954). And, as the collective-bargaining agreement was no longer in force at the time of the resignations, the retention-of-membership provision was no longer in effect. Finally, the trial examiner found no evidence that the members knew of the Union’s “established practice” of accepting resignations only during the annual 10-day escape period, and in the absence of such knowledge that practice cannot be enforced.
The reasonableness of the fines imposed by the Union is not in issue here.
Counsel for respondent stated in oral argument that the Union membership ultimately voted to terminate the strike and accept the company’s offer. Tr. of Oral Arg. 29.
The decision in Scofield v. NLRB, 394 U. S. 423, 430 (1969), indicated, in dictum, that an employee could avoid a union productivity rule by resigning from membership. That statement. should not be construed to mean that employees can never bind themselves to fulfill union obligations where, as here, the enforcement of that obligation is essential to maintain union discipline during a strike. See Recent Cases, 85 Harv. L. Rev. 1669, 1674-1675, n. 23 (1972); Recent Decisions, 40 Geo. Wash. L. Rev. 330, 338-339 (1971).
In other contexts it has been held that § 7 rights may be waived. E. g., NLRB v. Shop Rite Foods, Inc., 430 F. 2d 786 (CA5 1970). Indeed, this Court’s opinions in Allis-Chalmers and Scofield implicitly recognize that § 7 rights can be waived. NLRB v. Allis-Chalmers Mfg. Co., 388 U. S. 175, 200 (1967) (Black, J., dissenting).
The General Counsel argued before the trial examiner that the fines imposed were unreasonable, and that the imposition of an unreasonable fine would constitute a violation of § 8 (b) (1) (A). The trial examiner did not pass on this issue, as he concluded that the imposition of any fine on employees who resigned from membership in the Union and returned to work violated § 8 (b) (1) (A). Neither the Board nor the Court of Appeals passed on this issue, and it has not been argued before this Court.