Lots of operations put small amount people in danger in order to protect a larger group, that's essentially the whole idea behind police, military, special forces and related groups.
People become moles for the greater good, usually, or protection. Sometimes it works out, sometimes not.
It's the opposite, the folks willing to become moles for the US are usually the most corrupt and least scrupulous of their cohort. Or at least that's the common sentiment in the bureaucracy of every Asian country I've heard of.
For example, rumours in the grapevine suggest that by 2013 all the efforts of the various agencies combined managed to plant a grand total of 1 mole into the State Council of China.
That's after 40 years of trying since the CIA office in Beijing was established, and likely hundreds of billions spent trying to secure promotions, favours, pay bribes, etc. Allegedly, the CIA had kept index cards on every prospective career official in China, and the filing cabinets took up a football pitch of floorspace.
This amounted to nothing pretty soon after, which would explain the geopolitical movements since.
People become moles for the greater good, usually, or protection. Sometimes it works out, sometimes not.