Opinion for the Court filed by Circuit Judge SILBERMAN.
Concurring Opinion filed by Circuit Judge MIKVA.
Dissenting Opinion filed by Circuit Judge HARRY T. EDWARDS.
SILBERMAN, Circuit Judge:
This appeal challenges a preliminary injunction that, as modified by the district court, forbids a number of agencies in the Executive Office of the President (“EOP”) from conducting random urinalysis drug-testing of employees with “secret” national security clearances. 712 F.Supp. 986. We hold -that the prior decisions of the Supreme Court and of this court establish the validity of random drug testing of such personnel and, therefore, reverse the district court’s decision.
I.
In 1986, President Reagan promulgated Executive Order No. 12,564, the goal of which was to create a “drug-free Federal workplace.” 51 Fed.Reg. 32,889 (Sept. 17, 1986). Pursuant to the order, in July 1988 the EOP issued its own Drug-Free Workplace Plan covering its constituent agencies. Each agency designates employees whose position requires random urinalysis testing. The actual procedures for choosing the individuals to be tested, obtaining urine specimens, and testing the specimens for drugs are substantially identical to the procedures this court upheld with respect to personnel holding “Top Secret” security clearances in Harmon v. Thornburgh, 878 F.2d 484 (D.C.Cir.1989), cert. denied, — U.S. -, 110 S.Ct. 865, 107 L.Ed.2d 949 (1990). These procedures “significantly minimize” intrusion on the employees’ privacy expectations. National Treasury Employees Union v. Von Raab, 489 U.S. 656, 109 S.Ct. 1384, 1394 n. 2, 103 L.Ed.2d 685 (1989).
On May 19, 1989, the district court entered a preliminary injunction barring the government from random drug testing of plaintiffs in the top secret and secret categories. After our decision in Harmon, the district court modified the injunction by excluding from its scope the personnel holding top secret clearances. The government now appeals the temporary injunction forbidding the testing of the personnel holding secret clearances.
II.
We are guided of course by those decisions of the Supreme Court and of this court that bear on the question. The framework of the analysis of challenges to drug testing is provided by Von Raab and Skinner v. Railway Labor Executives’ Association, 489 U.S. 602, 109 S.Ct. 1402, 103 L.Ed.2d 639 (1989). Von Raab and Skinner establish the following propositions: urinalysis testing is a significant intrusion into the privacy interests of employees and as such is a search within the Fourth Amendment, see Von Raab, 109 S.Ct. at 1390; Skinner, 109 S.Ct. at 1412-13, and it does not require a warrant, a probable cause, or any level of individualized suspicion, see Von Raab, 109 S.Ct. at 1390; Skinner, 109 S.Ct. at 1416-17, but is instead governed by the balancing process weighing the interests of the government qua employer against the privacy interests of the employees, see Von Raab, 109 S.Ct. at 1390; Skinner, 109 S.Ct. at 1413-14. Those governmental interests powerful enough to justify urinalysis testing include the public security interests that can be endangered by employees with access to national security information, see Von Raab, 109 S.Ct. at 1396-97, by personnel who carry firearms in the course of their employment, see National Fed’n of Federal Employees v. Cheney, 884 F.2d 603, 612-13 (D.C.Cir.1989), cert. denied, — U.S. -, 110 S.Ct. 864, 107 L.Ed.2d 948 (1990); by personnel with access to drugs or who prosecute drug cases, see Harmon, 878 F.2d at 490; and by employees who control or have access to dangerous instru-mentalities, see Cheney, 884 F.2d at 610-11; American Fed’n of Gov’t Employees v. Skinner, 885 F.2d 884, 891-92 (D.C.Cir. 1989), cert. denied, — U.S.-, 110 S.Ct. 1960, 109 L.Ed.2d 321 (1990). All of these propositions are now part of settled Fourth Amendment law.
Von Raab further recognized that the government has a compelling interest in the discovery of drug use to protect "truly sensitive information.” But the Court in that case used both the terms “sensitive” and “classified” in such a fashion as to suggest that it was unsure of the strength of the government’s interest in protecting the information to which some of the employees involved — such as “animal caretaker^],” “baggage clerk[s],” and “co-op students]” — had access. Von Raab, 109 S.Ct. at 1396-97. Indeed, it was not clear that those employees had security clearances of any kind.
Subsequently, in Harmon we were faced with the question of the strength of the government’s interest in the protection of top secret information. The court (unanimous on this point) was unequivocal in its assessment of this interest: “[w]hatever ‘truly sensitive’ information includes, we agree that it encompasses top secret national security information.” 878 F.2d at 491 (footnote omitted). We therefore held that a person with a top secret clearance generates sufficiently grave potential risk to national security to make the decision to conduct random urinalysis testing reasonable regardless of any other attendant circumstances. Appellees argue that Harmon short-circuited the Von Raab/Skinner balancing test by disregarding the employees’ privacy interest and by not examining the degree of supervision to which the employees were subject. Just so — in any balancing test, certain factors may be decisive whenever they are present. Implicitly, but necessarily, Harmon assumed that the degree of supervision of a holder of top secret clearance was irrelevant and that he or she had diminished privacy expectations. The government’s primary concern with regard to material classified as top secret (or secret) is that an employee could be induced, perhaps by a blackmailer who is aware of employee’s illegal drug use, to disclose the information. See Department of Navy v. Egan, 484 U.S. 518, 528, 108 S.Ct. 818, 824, 98 L.Ed.2d 918 (1988). If an employee using illegal drugs has access to the information because of his clearance, the degree of his supervision presumably would not reduce the risk of disclosure. As for the privacy interest, a number of cases, besides Harmon, have recognized that holders of security clearances have less of an expectation of privacy. See Von Raab, 109 S.Ct. at 1397 (background investigations “may be expected to dimmish [the employees’] expectations of privacy in respect of a urinalysis test”); Thomson v. Marsh, 884 F.2d 113, 115 (4th Cir.1989).
Harmon's, insight that, at its peripheries, a balancing test may be presumed always to yield one result is hardly novel. The Supreme Court has preserved the overall balancing test of “reasonableness” required by the Fourth Amendment while articulating several per se rules of specialized application which automatically allow searches of pre-determined scope under specified circumstances. See, e.g., United States v. Ross, 456 U.S. 798, 102 S.Ct. 2157, 72 L.Ed.2d 572 (1982) (all containers within an automobile are subject to a search if there is cause to search the automobile itself); New York v. Belton, 453 U.S. 454, 101 S.Ct. 2860, 69 L.Ed.2d 768 (1981) (the entire inside area of the automobile can be presumed to be within the reach of the arrestee and is subject to a search incidental to a lawful arrest); Chimel v. California, 395 U.S. 752, 89 S.Ct. 2034, 23 L.Ed.2d 685 (1969) (search incident to a lawful arrest may extend to any area “ ‘within [ar-restee’s] immediate control,’ ” id. at 763, 89 S.Ct. at 2040). Indeed, a number of drug-testing cases in this court are premised on the assumption that the commands of Von Raab can be fulfilled by drawing clear demarcation lines. We consistently assumed that some jobs performed by the federal employees create sufficiently grave risks as to make random drug testing reasonable in all circumstances. Thus, we did not place great weight on the precise type of weapons carried by the guards when we approved random urinalysis testing of them, Cheney, 884 F.2d at 612-13, and we did not base our decision that bus drivers can be tested on the precise number of people they transport, AFGE, 885 F.2d at 893.
Appellees argue, nevertheless, that the change of the threat from “exceptionally grave damage to national security” (top secret) to “serious damage to national security” (secret) is of constitutional magnitude and that we are, therefore, required to apply a different analysis than we did in Harmon — particularly because appellees imply that Harmon was itself a dubious interpretation of Von Raab and should not, therefore, be extended. We do not see, however, how the constitutional permissibility of drug testing can depend on whether the employees tested have access to information the disclosure of which causes “only” serious damage as opposed to exceptionally grave damage to national security. Nothing in Fourth Amendment jurisprudence suggests that a distinction of constitutional principle can be drawn between the two categories. That is why the dissent’s effort to draw a constitutional “line in the sand” between top secret and secret (interpreting the word “reasonable” in the Fourth Amendment) seems so labored.
And none of the claimed distinctions raised by appellees between this case and Harmon are determinative. The privacy interests of employees holding top secret and secret clearances are not significantly different: in both eases the employees know that their conduct on- and off-work is of significant concern to the federal government and that at periodic intervals the government will conduct further inquiries into their behavior and associations. See, e.g., 32 C.F.R. Part 154.19 (1989). The frequency of exposure to secret documents (or lack of it) is not crucial; in Harmon, this court held that for employees with top secret clearances, random urinalysis tests are permissible regardless of the fact that some employees may be rarely, if ever, exposed to such materials. “The whole point of granting top secret security clearances in advance is to provide flexibility, to ensure that employees can be given access to top secret materials as soon as the need arises.” Harmon, 878 F.2d at 492. Similarly, the closeness of supervision is non-dispositive in this context. Harmon rejected the argument that employees in a “traditional office environment” (one of the factors mentioned in Von Raab, 109 S.Ct. at 1397, as lessening the need for testing) are necessarily immune under the Fourth Amendment from random testing. Harmon, 878 F.2d at 492. We cannot imagine, for instance, the permissibility of testing a holder of a secret clearance turning on whether he normally worked next door to a supervisor or on the floor below.
* * * * * *
The order of the district court is reversed.
. Pursuant to the Executive Order 12356, there are three levels of national security classification: top secret, secret and confidential. "Top Secret" information is information "the unauthorized disclosure of which reasonably could be expected to cause exceptionally grave damage to the national security." Id. § 1.1(a)(1). "Secret” information is information "the unauthorized disclosure of which reasonably could be expected to cause serious damage to the national security.” Id. § 1.1(a)(2). “Confidential” information is information “the unauthorized disclosure of which reasonably could be expected to cause damage to the national security.” Id. § 1.1(a)(3).
. Even if we thought Harmon was in error in presuming the results of the balancing test, we are not free to reexamine its holding other than en banc.