 Because they have never shown any outside experts concrete proof of their having successfully extracted the plutonium from their reactors, nor that they have managed to perform the complicated chemistry and engineering necessary to develop a prototype nuclear weapon design , and have not performed the requisite first nuclear test , their nuclear status, though declared, is being viewed as somewhat ambiguous.
<clarity>  Because they have never shown any outside experts concrete proof of their having successfully extracted the plutonium from their reactors, nor that they have managed to perform the complicated chemistry and engineering necessary to develop a prototype nuclear weapon design , and have not performed the requisite first nuclear test , their nuclear status, though declared, is being viewed as somewhat ambiguous.
 Because they have never shown any outside experts concrete proof of their having successfully extracted the plutonium from their reactors, nor that they have managed to perform the complicated chemistry and engineering necessary to develop a prototype nuclear weapon design , and have not performed the requisite first , their nuclear status, though declared, is being viewed as somewhat ambiguous.