"After Hamid's case, we think the threat is becoming serious."

At least the immediate threat of invasion had become more remote.

The more he threatened me, the less believable his threats became.

The company never took legal action, but its threats became known and chilled scientists to the bone.

The threat of Soviet armored forces and all-weather attack operations had became more serious.

And I moved now because the threat in the air had become active: and this danger was the worst.

Meanwhile, threats like biological and chemical weapons are becoming more menacing.

Since then, the threats have become almost as common as physical education or study hall.

At some level that is hard to define, we believe the threat had not yet become compelling.

At a time when threats are becoming increasingly serious, it is vital for us to protect these exceptional natural resources better.