Why the Spy Bosses Don't Always Like Spy Purges

TIME.com: Presumably the U.S. expulsion of diplomats accused of spying is retaliation for FBI counterintelligence officer Robert Hanssen, who turned out to be a double agent?

Elaine Shannon in Washington: The U.S. certainly had to do something about Hanssen's handlers. From a public relations point of view, they had to make clear that we know who you are and this sort of thing won't be tolerated.

Beyond Hanssen, though, getting rid of a larger number of Russian agents solves a different kind of problem. The FBI is under severe budget constraints. They have to maintain their number of agents at current levels or even reduce them through attrition. Their resources for surveillance are shrinking. So if you reduce the number of agents who have to be watched, you manage your resources better. An SVR [the Russian counterpart to the CIA] agent may meet an asset or make a dead drop only once every 90 days or so. But you have to watch him all the time, because if you miss him on the 90th day, which happens to have been a Sunday night, you could miss a year's work. So if you're seriously watching someone, you have to have three people on the job, in rotating shifts. Expelling a large number of agents reduces the workload, and better manages the budget.

President Bush, of course, also has domestic and geopolitical motives for making a statement that we're not warm and fuzzy with the Russians. It's the most dramatic move against the Russian community in Washington since President Reagan's mass expulsion in the early 1980s. President Bush is the most conservative president since Reagan; he's more conservative than his father. So he may also be out to reassure conservatives that the Bush administration doesn't view Russia as simply another European nation.

TIME.com: What's the response in Moscow?

Andrew Meier in Moscow: Moscow has responded by promising a tit-for-tat expulsion. Government officials characterized the U.S. decision as a "Cold War" move. Unofficially, though, I spoke to a couple of people in the intelligence community here, who said President Bush was living in a time warp. This hasn't been done since President Reagan did it in the 1980s, and it's being perceived as a crude slap in Russia's face, motivated by the need for damage control over the Hanssen case.

Russians are particularly skeptical of the numbers. Some reports are saying that up to 50 officials will be sent home on charges of spying. There's some doubt here over whether that number could seriously have been suspected of espionage — Moscow sees this as hype and grandstanding. The Russians see this as overreaching, and a dangerous early taint on the relation between the two countries. They see it as in keeping with some remarkably hostile comments on Russia recently by senior U.S. officials such as Defense Secretary Rumsfeld.

Of course what you have to realize here is that whether in Washington or Moscow, decisions to expel the other side's spies come from the politicians, not the intelligence community. Because when you kick out spies en masse, you have to start from scratch again, in identifying the spies sent to replace those expelled. And if you've managed to recruit any spies on the other side, it's certainly not in your interests to send them home. But if you're doing a mass expulsion, you can't exempt your double agents, for fear of exposing them. So it's unlikely that the intelligence community in Washington chose the expulsion option. It's seen as more of a political move.