SEOUL — With so many weapons tests at the start of each year, this has never happened before. Many things make Kim Jong Un want to hurry. China will soon be in the center of the world’s attention when it hosts the Winter Olympics. In March, South Koreans will vote for a new president. This person could set the country on a new path toward the north. Pyongyang’s threats could make Beijing look bad at the Winter Olympics or give power to a more hard-line South Korean candidate.

On the other hand, Mr. Kim is also keeping his promise to modernize and improve the country’s war deterrent. During the last few years, the Kim regime hasn’t tried to make long-range or nuclear weapons work. Instead, Pyongyang has made progress in hypersonic, submarine-launched, and shorter-range missile technology that is better for fighting close to home.

During the last 12 days, there have been four tests. On Monday, two tactical-guided missiles were fired from the air. It’s the most tests the Kim regime has ever conducted in such a short time.

This could be even more important if Pyongyang decides to restart nuclear talks. People in the country don’t think that disarming could make the country less safe, but it also shows that the country has more military power if talks don’t work out, says Kim Young-jun, a professor at the Korea National Defense University in Seoul.

Even if talks don’t work out, “Kim Jong Un” needs to show his people that we have strong military power, so that even if they don’t work out, we have plans for a war scenario, said Kim, who advises the South Korean government on national security.

In 2018, North Korea switched from testing to talks in 2018. This led to three meetings between then-President Trump and Kim Jong Un. But the United States and North Korea haven’t met in person for more than two years. A year-end speech by Kim Jong Un didn’t say anything about the United States.

People in North Korea have recently been hit with sanctions from the U.S. because of the Kim regime’s ballistic-missile launches. The U.S. has also proposed new sanctions at the UN. Tests like this one by North Korea aren’t allowed by UN Security Council rules.

As North Korean weapons tests go up, both sides have “dangerously contradictory myths” about each other, says Jessica J. Lee, who is a Korea expert at the Quincy Institute for Responsible Statecraft, a think tank in Washington.

Lee said that with more sanctions against the most closed economy in the world, the U.S. will only make the Kim regime’s nuclear buildup look better to its people. “North Korea’s demand for concessions up front is nothing more than political theater. Japan and Russia, which have veto power on the U.N. Security Council, want to ease sanctions on North Korea. They could stop the U.S. from adding more sanctions.

Katsuhisa Furukawa, a former member of the UN panel that monitors sanctions enforcement against North Korea, says that punishing Pyongyang for its continued ballistic-missile tests can be done by better enforcing the sanctions already in place. But Washington would have to make punishing Pyongyang a bigger political priority than it is now.

He said the Biden administration spends so much time and money on Iran, Afghanistan, and China. There’s a problem with North Korea, but not so much with South Korea.

The pandemic has cost North Korea a lot of money because it has had to close off its borders to stop the spread of the disease. The country says there have been no COVID-19 cases there. It has turned down millions of vaccines from foreign aid groups.

Only in the last few days has North Korea been able to send some cargo trains to China, which is its biggest supporter and ally. The relationship between the two Communist countries has been tense during Kim Jong Un’s 10 years in power. This relationship has become better in recent years, with Kim Jong Un praising the outgoing Chinese ambassador in Pyongyang for setting up a “fresh high point” between the two countries last month.

When Kim Jong Un became the leader of North Korea 10 years ago, it could have been the hardest thing he had ever had to do. The Wall Street Journal looks at how the North Korean leader is dealing with the economic fallout from the pandemic, which has overshadowed weapons tests and strained relations with the United States.

In the past, China’s most important diplomatic events have been interrupted by North Korean weapons  tests. In May 2017, North Korea fired a ballistic missile as Chinese President Xi Jinping held a meeting of world leaders to start China’s Belt and Road project. Months after North Korea did a nuclear test, Mr. Xi met with the leaders of other major emerging economies.

People who study Chinese foreign policy at the Brookings Institution say that Pyongyang is likely to keep making decisions based mostly on its own interests and long-term goals. “China has never been able to make North Korea do what it wants,” she said.

On his guns: Mr. Kim hasn’t kept quiet about his plans. A year ago, he came up with a plan to modernise the country’s conventional weapons. He wanted missiles to get smaller, lighter, and fly farther. He talked about a nuclear-powered submarine, a hypersonic warhead, and guided multiwarhead rockets in a way that was very unusual.

North Korea didn’t do much during the first few months of Joe Biden’s presidency. He flew cruise missiles and tested a ballistic missile in March. Lay low this summer. But since September, North Korea has launched eight rockets that have shown off a number of weapons that Kim Jong Un talked about in his policy speech last year, like the rockets.

As a former three-star South Korean army general says, “The message is clear: We’re building up our abilities and doing the same thing we said we would do.” Yes, they do what they say they will.