They’re doing it again. The North Koreans, after respecting China’s request not to test-fire missiles during the Beijing Olympics, are firing away. By now Kim Jong-un has ordered eight test shots this year.

The latest, the North has said, was a “reconnaissance satellite” that South Korea’s defense ministry says flew 185 miles before landing off the east coast. That’s hardly a satellite, but perhaps the purpose was to test cameras and other gear before test-firing an intercontinental ballistic missile capable of hitting targets in the U.S. The North last test-fired an ICBM in November 2017.

What is the meaning of these tests and how much do we have to fear? The answer is that North Korea is challenging not only South Korea but also the U.S.

Right now, President Joe Biden is promising another $350 million in emergency military aid for Ukraine, much of it in the form of anti-tank and anti-aircraft weapons needed right away to stop Russian forces before they’re able to take over the capital, Kyiv, and other key cities. Quite soon, Biden may ask Congress to approve more than $6 billion to keep Ukrainian resistance going in what’s likely to be a prolonged struggle. But the U.S. is still not ready to place advisers on the ground, much less commit full-scale combat units for what would then turn into a full-scale war between the U.S. and Russia.

Instead, the U.S. and its NATO allies are leaving the Ukrainians to fight on their own against the Russian assault, including tanks and airstrikes. The nature of the American response raises questions about the degree to which Biden would rush to the defense of South Korea if the North Koreans, with the support of the Chinese and Russians, decided the time was ripe to stage the Second Korean War.

South Korea, to be sure, is not Ukraine. The Americans fought a terrible war on behalf of the South Koreans after the North Korean onslaught in June 1950, and the U.S. is still bound to South Korea by a defense treaty under which 28,500 U.S. troops remain in the country.

The alliance would appear quite strong, but the response of China and now North Korea to the Russian invasion of Ukraine shows the tight relationship between North Korea and the two great powers that prevented its defeat in the Korean War. The Chinese support the Russians, and a North Korean commentary accuses the U.S. of pursuing “global hegemony and military supremacy in disregard of the legitimate demand of Russia for its security.”

The commentary, on the website of the North Korean foreign ministry, drew a parallel between Russia and North Korea, which always says it needs nuclear warheads and missiles for security against the U.S.

With days to go before South Korea’s presidential election next Wednesday, North Korea is eager to influence the outcome. The message is clear. The candidate of the ruling Minjoo or Democratic Party, Lee Jae-myung, pursuing reconciliation, would respond to missile tests with pleas for dialogue and understanding. He’s urging the U.S. to soften its policies, ease up on sanctions and go for an end-of-war declaration that would lead to a peace treaty in place of the armistice that ended the Korean War in July 1953.

North Korea’s missile and nuclear strength is obviously a deep point of pride under the Kim dynasty that has ruled the North since the Soviet Union installed Kim Il-sung, a former officer in the Soviet army, in Pyongyang after the Japanese surrender and the division of the Korean peninsula in August 1945.

There’s no way that Kim Il-sung’s grandson, Kim Jong-un, is going to give up his precious nukes and missiles, but the candidate of the opposition People Power Party, Yoon Suk-yeol, supports U.S. demands for denuclearization. The North, insisting Washington drop sanctions, has yet to respond to repeated calls for talks.

Seoul, wary of offending either China or Russia, is going along with sanctions against Russia but appears highly uncertain as to what to do. Moon may deplore the invasion of Ukraine but does not refer to Vladimir Putin by name or talk about democratic values and human rights.