Some of the nation’s best-known companies are grappling with the fallout from explosive disclosures from whistleblowers—pain that’s likely to throb for years and result in tens of millions of dollars in legal fees.

Perhaps it all could have been avoided had the companies been truly open to dissent in their ranks, with a culture that rewarded employees for bringing potential ethical and legal lapses to the attention of top managers, who would decisively act to do the right thing.