Mr. Eberstadt wrote last week: "Each new round of North Korean nuclear provocations has generated clear-cut benefits for the North Korean state, rather than incontrovertible costs.

Congress also faces a second set of issues with less clear-cut political benefits that will be particularly challenging in an election year.

No single treatment type has revealed clear-cut benefits in comparison to others, treatment for all cases remains problematic.

But it is becoming increasingly apparent how little of the new knowledge has translated into clear-cut benefits.

Also, few studies show clear-cut benefits and most leave some uncertainty.

Most stock market professionals, while seeing clear-cut benefits from the lower dollar, are privately worried that the currency's slump could prevent interest rates from going any lower.

The virus changes so frequently, and so unpredictably, that the clear-cut clinical benefit of surveillance - an accurate vaccine developed in a timely manner - is often out of reach.

But it is uncertain whether this swifter response has produced clear-cut medical benefits.

Maj. Gen. Harry Wyatt III, the adjutant general of Oklahoma, said the alert, which should lead to mobilization orders later in the year, had one clear-cut benefit.

Apple and Google are wiping the floor with them because we ran out of features to add that offer a clear-cut benefit about 5 years ago.