In Japan, the prime minister said North Korea would be committing a "grave, provocative act" if it followed through on plans to launch a long-range rocket. South Korea warned of "searing consequences" if the launch went ahead. Moscow and Washington, which rarely agree on much of anything these days, both denounced Pyongyang's plans. Even China, North Korea's closest ally, said it was worried.
But in the end, the international outrage didn't make any difference. On Sunday, Pyongyang launched its rocket -- which it says was designed only to carry a satellite into orbit, but which much of the world insists was a camouflaged long-range missile test -- and then proudly proclaimed its success.
Because North Korea learned long ago that it could achieve a great deal with deliberate belligerence.
Here's a look at Pyongyang's provocations.
Years after North Korea first agreed to shut down its nuclear weapons program, even as it quietly built it up, Pyongyang no longer makes a secret of its ambitions. Its 2012 constitution enshrines its status as a nuclear state. When it set off its fourth nuclear weapons test just a few weeks ago, infuriating the international community, it called the explosion "a great deed of history."
The test "guarantees the eternal future of the nation," the government declared. If the statement was over the top, there was also truth amid the hyperbole.
North Korea is an impoverished nation with a military often reduced to using decades-old Soviet equipment. It is profoundly isolated, facing sanctions that cut it off from most international trade. Its leaders are mocked regularly in the Western media.
Nuclear weapons, though, make the world pay attention. Even to a country so poor that 24-hour electricity is considered a luxury.
North Korea's nuclear weapons technology has given it immense international negotiating power, allowing Pyongyang to alternate nuclear tests with talks to ratchet back its weapons programs. Over the years, those talks have resulted in billions of dollars in aid.
The nuclear tests are also powerful messages for domestic consumption, proof of how North Korean leader Kim Jong Un, like his father and grandfather before him, had developed the country's military technology to withstand the ever-looming threats of South Korea and the United States.
Or as Kim put it in his New Year's address: "If invasive outsiders and provocateurs touch us even slightly, we will ... answer with a merciless, holy war of justice."
Nuclear weapons are inherently dangerous, of course, but they are far more dangerous if they can be launched quickly against targets around the world.
That, however, requires missiles, along with the technology to miniaturize nuclear explosives so they can fit onto warheads.
In announcing its launch plans, Pyongyang insisted its intentions were peaceful, calling it part of a "space development program" and saying the rocket would carry an Earth-observation satellite.
Many experts believe the North's rockets look more like they are designed to carry satellites into space -- and less like long-range missiles -- but the technology is similar, and forbidden by a series of U.N. resolutions.
As a result, much of the world denounced the Sunday launch as yet another ballistic missile test, and one more step toward a North Korean arsenal of nuclear weapons capable of striking as far away as the United States.
The announcement was also quickly followed by demands to further tighten trade restrictions on North Korea, already among the most-sanctioned nations in the world. It also sparked renewed calls, particularly from U.S. officials, for China to exert pressure on Pyongyang. While Beijing quickly expressed regret Sunday that North Korea had "obstinately insisted in carrying out a launch," it also pushed back against simply ratcheting up sanctions.
China's U.N. ambassador, Liu Jieyi, said any new U.N. resolution should "do the work of reducing tension, of working toward denuclearization."
Beijing has also made clear it believes there is plenty of blame to go around, and that it does not like being lectured to by Washington.
Soon after the January nuclear test, China's official Xinhua News Agency said the United States was responsible for much of the tension on the Korean Peninsula, saying "it boils down to Uncle Sam's uncompromising hostility ... flaring up the country's insecurity and thus pushing it toward reckless nuclear brinkmanship."
Such talk is welcome in Pyongyang, which has long portrayed itself as a courageous nation standing up to American aggression. Strained relations between Beijing and Washington also give North Korea more room for its own diplomatic maneuvering.
What happens when you want to demonstrate your military might but your technology isn't quite ready? If you're North Korea, experts say, sometimes you fake it. Or at least you exaggerate.
Pyongyang called its January nuclear blast a successful test of a hydrogen bomb, proof that North Korea was now "equipped with the most powerful nuclear deterrent."
Well, probably not. Weapons experts said there was little chance that Pyongyang had detonated an H-bomb. At best, they said, Pyongyang had set off a "boosted" explosion, which uses hydrogen isotopes but has far less strength than a traditional two-stage hydrogen bomb.
Or take North Korea's purported submarine-launched ballistic missiles.
In 2015, when North Korea announced it had successfully launched a missile from a submarine, experts said it may have actually been fired from an underwater testing barge.
Then, last month, a North Korea television report appeared to show leader Kim Jong Un proudly watching a successful underwater launch of a KN-11 missile. But detailed analysis of the footage done at the Middlebury Institute for International Studies, a leading proliferation research center in Monterey, California, instead found a carefully edited collection of video clips. Hidden amid the splicing was a completely different reality, they said. The missile, the Middlebury scholars found, most likely exploded moments after leaving the water.