There were supposed to be no electronic spies operating within, but he never took that on faith.

Before he left England he had been sent on a special course for spies operating in enemy hands.

A number of suspected spies operating in or near Kristiania were investigated.

I said, "You act pretty big for a lousy spy, or counterspy, operating in a foreign country, probably without permission."

There are spies operating everywhere, and we know who most of them are.

These men happened to be the eight top-notchers of all foreign spies operating in the United States.

The United States has fewer than 5,000 spies operating around the world, for example, but 30,000 eavesdroppers.

A legal resident spy operates in a foreign country under official cover (e.g. from his country's embassy).

American spies, the Swiss argue, operated freely from here.

For the most part, spies operating out of embassies gather little intelligence themselves and their identities tend to be known by the opposition.