necessary evil

1.
globalUSUKneutralformal
- Something undesirable or harmful that is accepted because it is required to achieve a greater good or to avoid a worse outcome.
- A pragmatic compromise that, although unpleasant, is considered unavoidable in a given situation.
2.
globalneutralphilosophical
- An evil or morally objectionable thing regarded as unavoidable in the pursuit of some moral or practical aim.
- An acknowledged moral drawback tolerated for the sake of larger benefits or necessities.

Examples: