the "no law to apply" standard of Overton Park. We disagree, however, with that court's insistence that the "narrow construction" of § (a)(2) required application of a presumption of reviewability even to an agency's decision not to undertake certain enforcement actions. Here we think the Court of Appeals broke with tradition, case law, and sound reasoning.
Overton Park did not involve an agency's refusal to take requested enforcement action. It involved an affirmative act of approval under a statute that set clear guidelines for determining when such approval should be given. Refusals to take enforcement steps generally involve precisely the opposite situation, and in that situation we think the presumption is that judicial review is not available. This Court has recognized on several occasions over many years that an agency's decision not to prosecute or enforce, whether through civil or criminal process, is a decision generally committed to an agency's absolute discretion. See United States v. Batchelder, 442 U. S. 114, 123–124 (1979); United States v. Nixon, 418 U. S. 683, 693 (1974); Vaca v. Sipes, 386 U. S. 171, 182 (1967); Confiscation Cases, 7 Wall. 454 (1869). This recognition of the existence of discretion is attributable in no small part to the general unsuitability for judicial review of agency decisions to refuse enforcement.
The reasons for this general unsuitability are many. First, an agency decision not to enforce often involves a complicated balancing of a number of factors which are peculiarly within its expertise. Thus, the agency must not only assess whether a violation has occurred, but whether agency resources are best spent on this violation or another, whether the agency is likely to succeed if it acts, whether the particular enforcement action requested best fits the agency's overall policies, and, indeed, whether the agency has enough resources to undertake the action at all. An agency generally cannot act against each technical violation of the statute it is charged with enforcing. The agency is far better equipped than the courts to deal with the many variables in-
