North Korea is escalating its missile and rocket threats, with South Korean military authorities and foreign policy makers on alert and trying to grasp the motives behind the latest provocations.

North Korea fired 46 short-range rockets from its east coast over the weekend. It fired 30 FROG ground-to-ground rockets into the East Sea early Saturday, followed by 16 more early Sunday morning.

The North began firing the latest series of short-range missiles and rockets on Feb. 21 and the Sunday firing was the seventh of its kind in about a month.

It is believed that the North is ratcheting up the provocations in part to counter the ongoing South Korea-U.S. joint military exercise. Also, the upcoming summit talks of the leaders of South Korea, the United States and Japan in The Hague may have prompted the North to step up its show of force.

It is usual for the North to resort to saber rattling whenever it deems necessary. Yet the latest series of provocations should raise an alarm bell. Some South Korean military experts point out that the North is increasing the number of rockets fired each time, with shorter intervals between firings. They note that even the much more affluent South Korean military would not test-fire such expensive rockets so profusely.

Of no less importance is the timing of the most recent rocket launches. According to the Joint Chiefs of Staff, the North fired rockets between 4 a.m. and 6:10 a.m on Saturday and between 00:52 a.m. and 2:31 a.m. on Sunday. It is very rare for the North to fire missiles or rockets in these wee hours.

It goes without saying that these are the best time periods for surprise attacks. This point should not be ignored because the North may be practicing for a surprise attack similar to the artillery shelling of Yeonpyeongdo Island in 2010. The South Korean military should remain vigilant since it is possible that the Kim Jong-un regime will further heighten tension on the peninsula.

Equally worrisome is the possibility of the North conducting a fourth nuclear weapon test or firing a new intercontinental ballistic missile. This could become a reality because the North has reactivated the nuclear reactor in Yongbyon. Experts believe that by this summer the North will have enough plutonium to build a nuclear bomb from the reactor’s spent fuel.

It is urgent for the international community to contain the military threat posed by the North’s conventional and nuclear arms. Let us hope that during their gathering in The Hague the leaders of the three countries will find at least a clue to persuading or pressuring the North in this regard.