Why are captured enemy spies executed?

Or, at least, subject to execution?

Other captured enemy troops are held in captivity. Executing any of them would be a war crime (except, of course, if they were tried and convicted for some capital criminal offense).

When and why did this “policy” originate? Why are spies so uniquely loathsome that they must be put to death? Is it because of the huge amount of damage they can do? Is it because the role of a spy was considered “undignified” and thus not worthy of life?

Thanks!

Are they? Maybe by governments that don’t respect human rights in general or the Geneva conventions. If you execute people for lesser crimes, it’s not too surprising. Now, if you’re talking about executing a citizen for spying for the enemy, they have committed treason, which is usually one of the last holdouts for capital punishment. Probably due to the severity and general unseemliness of it.

It gives the capturing side the most leverage to get them to cooperate.

My understanding of the Geneva Conventions is that uniformed enemy soldiers who are captured must be treated as prisoners of war and not tortured or killed. But spies are by necessity not in uniform, so that the Geneva Conventions do not apply.

Right, Geneva Convention explicitly does not apply to spies. Spies have been subject to execution basically since “forever.” While it used to be pretty common for people to execute all captured prisoners in a war, spies have just always been particularly reviled. Being a spy has always been a dangerous game.

However I’m not sure how many countries still actually execute spies. No country in the EU executes anyone or has the death penalty as a law. The United States hasn’t executed anyone for espionage in over fifty years, and we’ve caught a few big ones in that time. It seems like it’s become more common to just kick them out of the country, a lot of spies work out of embassies and when caught they are just quietly sent home. When more elaborate and flashy spies (like all the Russian spies caught in New York awhile back) it seems we do public trades for people.

Russia doesn’t execute anyone anymore (although it is still codified), but obviously it’s “possible” that Russia might still “liquidate” a captured spy out of the public eye. China still executes people but I think they’d probably return spies to most countries.

Might be off topic, but why would they return them? Why not throw them in a prison to rot?

So you can trade them for your own captured operatives? And before I hear about the tired old refrain about China not caring much about the lives of its agents, there is a practical reason to do so, which is to raise morale to the extent that “if you are captured, we will bring you back”.

There are three categories of spies. Citizens of the nation doing the spying, citizens of the nation being spied upon, and citizens of a third nation. Only spies of the first kind are traded. Spies of the second kind are committing treason.

And the rationale behind why the Geneva Conventions applies only to uniformed soldiers: It’s expected in warfare that you’re going to kill the enemy, but ideally, you should try to avoid killing civilians. When the enemy clearly identifies themselves as such by wearing uniforms, this is relatively simple to do. However, if you get too many folks who are dressed as civilians but still attacking, it becomes very difficult for the other side to distinguish between valid targets and innocent bystanders. So such activity has to be discouraged as much as possible.

So far all the answers address the legality of executing spies during wartime, but not why any government would actually want to execute one. If I could hazard a guess at the latter, I’d say that it’s simply too dangerous to let the spy live. They may well have acquired valuable military and political intelligence before their capture; if you put them in a regular POW camp then they’ll probably tell their comrades these secrets, which in turn increases the likelihood of the information making its way back to their home country via camp escapees, prisoner exchanges, contact with partisans, double agents, etc. It’s much safer to ensure their silence by killing them.

It’s pretty simple:

Thanks for all those answers.

To clarify, I was thinking about spies during a ‘declared war’ such as WWII. And, in particular, about those individuals caught spying who were wearing either no uniform (i.e. in civilian clothing) or the uniform of the country they’re spying on. My question was prompted after reading about the execution of captured German soldiers who had been dressed as American troops during the Battle of the Bulge. It seemed to me that at the end of the day, they were just doing the same as their uniformed colleagues, i.e. trying to defeat their enemy.

psychonaut and Chronos have probably come closest to answering the most salient aspect of my question, that is, ‘why such spies are executed’.

Nope. Two executed for spying in 2008:

That article doesn’t indicate that the two spies were foreign nationals. Presumably they were Chinese citizens, so there was nowhere to “return” them to.

Pour encourager les autres.

They may also have been trained in such a way that makes them harder to contain or safely handle.

I’d say all of the above!

It is worth noting that not all spies captured by the British in WW2 were executed. Quite a few were turned as part of the Double X system to feed false information to the Germans. Giving the stark choice of work with us or be killed certainly focused the mind of the captured agent.

Right, I should have clarified you wouldn’t return/swap home grown spies. At least not normally, most countries take it pretty seriously when one of their own are spying. That’s why Aldrich Ames and Robert Hanssen got life sentences and there was never any talk of them being traded over to Russia.

Or more famously, why the American government executed Julius and Ethel Rosenberg instead of handing them over to the Soviet Union.

Shakester got it in one. If you don’t execute them, everybody will think about doing it, and that’s no way to survive as a country.