The Constitutional Court judges had barely left the chamber after removing South Korea's president from office. Supporters and opponents of the impeachment were still cheering and jeering on the streets, when the country's defence minister issued an urgent order to his generals: raise the alert level. An attack could be imminent.

Given South Korea's sudden political instability, Minister of National Defence Han Min-koo concluded, "It is possible that North Korea will make a strategic and operational provocation at any time."

He told his forces to "sternly respond."

It was the kind of order South Korea's military trains for and expects.

But what comes next in this country — an election will be held May 9, it was confirmed Wednesday — may be much more unpredictable when it comes to dealing with threats from the north: a new political direction and a new military policy that may not be as stern.

Park's 'iron will'

The corruption scandal around ex-president Park Geun-hye, 65, and the disgrace of her impeachment has left South Korea's conservative political fortunes in tatters.

And it's the only group her most ardent fans trust to take a hard line with North Korean leader Kim Jong-un and to protect against his weapons, just 50 kilometres away from the centre of Seoul.

Jang Hwa-young

'We need her to save us from the communists,' Jang Hwa-young said as he waved a huge Korean flag at a rally supporting Park outside the court. (Saša Petricic/CBC)

"We need her to save us from the communists," said Jang Hwa-young as he waved a huge Korean flag at a rally supporting Park in front of the court. He was crying at the thought of losing what he called her "iron will," and of handing power to what he called the "naive" opposition.

Indeed, as the nuclear threat from North Korea grew, Park and other conservative leaders in the past decade increased South Korea's military might and tied it more closely to the United States.

The two countries hold large-scale annual military exercises simulating an attack from the north. This year's is now underway and is expected to be the biggest ever, involving stealth fighters, strategic bombers, an aircraft carrier and hundreds of thousands of soldiers.

Washington also agreed last year to supply South Korea with a state-of-the-art missile system known as Terminal High Altitude Area Defense, or THAAD. Its implementation has been controversial among Koreans who feel it provokes the north and angers China, which thinks THAAD's powerful radar could be used to penetrate its military secrets.

Still, it became a centrepiece of Park's military response. 

At Seoul's invitation, Washington started installing the system this month. China has started a campaign of economic retaliation in response.

SOUTHKOREA-USA/AIRCRAFT CARRIER

A U.S. F18 fighter jet approaches the deck of an aircraft carrier during an annual joint military exercise called 'Foal Eagle' between South Korea and the U.S., in the East Sea, South Korea, on March 14, 2017. (Kim Hong-ji/Reuters)

Voters want change

But now Park is out. She faces 13 criminal charges for allegedly extorting companies for millions of dollars, accepting bribes from Korea's mammoth Samsung conglomerate and abusing her power. Prosecutors have announced that she will soon be summoned for formal questioning.

She has denied any wrongdoing.

"I apologize that I could not finish my mandate as president," she said in a statement after the verdict. "It will take time, but the truth will be revealed."

Korean voters may not wait for her truth. The millions who took to the streets in peaceful protests against Park want change. And those marches were peppered with signs rejecting THAAD.

When new presidential elections are held in early May, South Korea's majority seems ready to give the presidency to someone from the social-liberal Democratic Party, the main opposition.

A public opinion poll over the weekend gave its leading presidential hopeful, Moon Jae-in almost 30 per cent support, compared to nine per cent for the only high profile member of Park's party who was considering running, acting President Hwang Kyo-ahn. He announced today that he is not interested, complicating things further for a movement that's trying to avoid a humiliating loss.

Park's centre-right Saenuri Party even changed its name to the Liberal Korea Party, but that hasn't made voters any more sympathetic.

Alliance with U.S. 'important'

Moon has described himself as "America's friend," though he is much more skeptical about tying himself to Washington's policies and its military strategy in confronting North Korea.

In a TV debate among several opposition presidential hopefuls last night, Moon said he wants the new government to decide whether the THAAD system should be used.

Park verdict

People gather around a TV in a Seoul subway station to watch the Constitutional Court's verdict upholding the impeachment of President Park Geun-hye on March 10, 2017. (Saša Petricic/CBC)

"China's economic retaliation came as South Korea failed to make diplomatic efforts and made the decision in a hurried manner," he said.

And he wants to use dialogue as a means to reverse Kim Jong-un's arms program.

In an interview with the New York Times he said, "We must embrace the North Korean people as part of the Korean nation, and to do that, whether we like it or not, we must recognize Kim Jong-un as their ruler and as our dialogue partner."

That's been tried before with North Korea, and while it did increase co-operation and dialogue, it did not stop Pyongyang from continuing to develop nuclear weapons.

National security analyst Park Bynug-kwang, of the Institute for National Security Strategy in Seoul, agrees that diplomacy is important, but he says no matter who is elected, there will be immense pressure to maintain key elements of the conservatives' defence strategy in order to keep the country secure. 

Park Bynug-kwang

No matter who is elected to replace Park, there will be immense pressure to maintain key elements of the conservatives' defence strategy in order to keep the country secure, said national security analyst Park Bynug-kwang. (Saša Petricic/CBC)

"Any new president will also need to protect South Korea and the South Korean people. Therefore, he cannot easily change the decision on deployment of THAAD system," he says. "We need it."

Park also says rejecting THAAD risks damaging South Korea's vital partnership with the U.S.

"This deployment is a promise between the South Korean government and the U.S.A. government. If we don't deploy, then that means we have broken the promise with U.S.A. And that alliance is very important," he says.

The pressure to keep people safe, combined with the expectation of a break with the previous government and with policies that many here believe have only encouraged North Korea to be bolder and more belligerent — these are tough competing pressures for any new president.