When news broke that a bomb hidden inside a safe blew away the new Palestinian ambassador to Prague this week, one of his old colleagues in the Palestine Liberation Organization’s diplomatic corps told me grimly, ironically, “I was reminded of ‘the good old days.’”

The Czech police have suggested it was an accident: an explosive security device. The embassy staff say they doubt that, and had never heard of such a booby trap in a safe they’d used many times. Then unregistered weapons were found at the embassy. (The PLO has had diplomatic representation in several European capitals dating back to the 1970s, and some of those missions were used to hide arms for operatives in the early days.) The death is likely to remain an official mystery to law enforcement, but if indeed it was a murder, somebody will have gotten the message—and not just the victim.

In the Middle East, the Balkans and the Caucasus, after all, assassinations are an old and well-established form of communication perfected over the course of a thousand years. Indeed, as you’ll recall, the word “assassination” comes from the cult of the hashishin, the highly mythologized mystical dope-smoking agents of terror during the time of the Crusades who protected the interests of a Muslim sect holed up in the mountains of what is now Iran. (The popular video game Assassin’s Creed continues the legend.)

Just last week there were many reminders of the work done by today’s targeted killers: A car bomb in the poshest corner of Beirut took out former government minister Mohamad Chatah, a leading moderate opposed to Syrian President Bashar al-Assad’s influence in Lebanon. The alleged murderers of former Lebanese Prime Minister Rafic Hariri are set to go on trial in The Hague this month—but in absentia, and nine years after the killing. The former Israeli ambassador to Argentina just gave an interview claiming that most of the people who carried out horrific attacks on Jewish targets in Buenos Aires in 1992 and 1994 “are in another world, and this is something we did.” Last month, Lebanese authorities detained the head of a jihadist group, accused of bombing the Iranian embassy in Beirut, who may have had links to al-Qaeda but also was accused of ties to Saudi intelligence. On Friday the authorities announced, cryptically, he’d died in custody.

All this seems like the bad old “good old days” to veterans of Levantine intrigue because before Osama bin Laden’s attacks on New York and Washington in 2001, tit-for-tat killing was conducted like an ongoing conversation not only among Israel and its Arab and Iranian enemies, but among the Arabs themselves—between factions of the Palestinians, and between Iran and its exiled opponents. Too often, the United States, France and Britain got dragged into the middle of these murderous intrigues, appearing as clueless as a schoolboy trying to decipher cuneiform.

It was a cacophony of carnage, if you will, but one well understood by the central antagonists. "It's an ongoing game, playing by the rules of the Bible," a senior official in Israeli intelligence once told me, "and at a certain point there is a balance of terror where everyone knows what's expected."

Typically the assassins were secret agents or, more often, proxies with their own causes, which allowed some level of deniability for the governments that backed them. When the murderers were hostile to American interests, the governments were branded “state sponsors of terrorism.” When Washington deemed them friendly, they were carrying out “targeted killings” and “daring commando raids”; they were using “hit teams” to bring dangerous killers to justice and “freedom fighters” to kill enemies of the United States. Often, nobody admitted responsibility and the deaths just remained mysteries except, perhaps, to the groups that were targeted.

The aftermath of the 9/11 attacks and Bin Laden’s supranational jihad obscured the issue of “state-sponsored terror.” The elimination of arch-sponsor Saddam Hussein and the Arab spring have thrown the old balances out of whack, but the dialogue of death among the main players in the Middle East never stopped: a Hamas operative murdered by alleged Israeli agents in a Dubai hotel in 2010; top Syrian security officials, including Bashar Assad’s brother-in-law, blown up during a meeting in 2012; the mastermind of Saudi-backed anti-Assad security operations in Lebanon killed in a Beirut car bombing three months later—those are just a few examples.

Lebanon seems to be ground zero for “the assassination plague,” as a veteran CIA analyst calls it. It’s been a covert battleground for competing powers in the region for as long as anyone can remember, and the Syrian civil war next door has intensified the intrigues and treachery. As Beirut blogger Amal Ghandour wrote this week, quoting a local adage, in Lebanon “if you’re seeing straight, you’re cross-eyed.” But in today’s world, in fact, the plague’s infection has spread far and wide.

Washington used to try to keep its hands clean by banning assassinations, but its drones flying over Pakistan and Yemen have carried out so-called targeted killings on an industrial scale. The Council on Foreign Relations estimates 3,520 people have been taken out by the drones since 2004, 457 of them civilians. And while most of the dead have fallen under the general rubric “al-Qaeda,” some of them allegedly worked with the Pakistani intelligence services, which want their own proxies available for attacks in India and Afghanistan.

The medium is the message, as the saying goes: the bullet, the booby trap, the car bomb and, for that matter, the Hellfire missile that seems to come out of nowhere, demand a lot more attention than a diplomatic note, but they’re much less risky than wars among nations, and responsibility can be denied by the parties behind the killings even if nobody believes them.

Such actions are “something different than what we’ve come to think of as ‘terrorism,’” says Bruce Hoffman, director of the Security Studies Program at Georgetown University. They are “an instrument of foreign policy,” he says, and, in truth, they can be effective. “With assassinations in particular, the initial effect is useful: firstly, eliminating a stone in someone’s shoe and, secondly, sending a message.”

But Hoffman warns that such tactics have become extremely dangerous, especially when secret services use proxy groups to do the dirty work. The assassins, after all, have their own agendas. “There is always this assumption in state-sponsored terrorism that you [the state] can control your clients,” says Hoffman, “when in reality your clients can control you.”

One obvious example was the group of Arab mujahideen funded by the Saudis and the Americans to fight the Soviets in Afghanistan in the 1980s. Until the Russians pulled out, the muj were “freedom fighters.” But then, in the 1990s, they became al-Qaeda’s fighters.

The most catastrophic and certainly the most cautionary example of assassins getting out of control actually came in the Balkans 100 years ago this summer. As Hoffman recounts in his 2006 book, Inside Terrorism, the Serbian secret services hostile to the Austro-Hungarian Empire used Bosnian radicals as proxies to wage a campaign of terror. They knew the Bosnians had targeted the Austrian Archduke Ferdinand. But when the Serbs tried to call off the murder, they were too late. The Bosnian killers wouldn’t be stopped. That assassination in Sarajevo set off the chain of events that cost the lives of more than nine million combatants and countless civilians in World War I.

Can the Saudis control the jihadists they are cultivating? Can Iran rein in Hezbollah when or if the moment comes? Will the Israelis decide not to pull the trigger when an enemy is in their sights? Will Assad, barely in control of his country, completely lose the loyalty of his client killers? Will the Americans rethink their drones?

Probably not. And if not, there’s a line in a new report from Brookings that’s worth pondering: "Like 1914,” writes Margaret MacMillan, “we are living through changes in the nature of war whose significance we are only starting to grasp."