Normally a North Korean missile test would attract no more than ritual condemnation from world capitals. But this time the hermit kingdom has made itself an early test of Donald Trump's judgment. The missile was fired across the Korean Peninsula in the direction of Japan on Sunday and it would have been no coincidence that Trump was hosting a state visit by Japan's Prime Minister, Shinzo Abe, at the time.
The new President's response was suitably measured. Initially he declined to answer reporter's questions on the test, which suggests he wanted to be properly briefed first. Then, a joint press conference with Abe, who called the missile launch "absolutely intolerable", Trump said, "I just want everybody to understand and fully know that the United States of America stands behind Japan, its great ally, 100 per cent."
That restrained statement was no more than any US President would have made and it was encouraging to hear it in this President's characteristic phrases.
His restraint was all the more welcome for the fact that some analysts were suggesting the missile being tested could be the first stage of an intercontinental ballistic missile capable of reaching the Unites States.
In a New Year address, the North Korean leader, Kim Jong Un, said his country "had entered the final stage of preparation" for an ICBM capable of reaching the US. In response at that time, President-elect Trump tweeted, "It won't happen".