To resolve the issue of North Korea's nuclear and missile development, it is essential to deal with the situation calmly and persistently through a combination of applying pressure such as economic sanctions and holding dialogue, not only emphasizing military options.

The United States and North Korea have repeatedly exchanged hard-line rhetoric, as if to show no hesitation to go to war. The exchange of aggressive rhetoric may unnecessarily intensify tensions and lead to the outbreak of unanticipated situations.

The root cause of the problem lies with North Korea. It test-fired an intercontinental ballistic missile twice in July, making it realistic that North Korea will deploy nuclear missiles that have the U.S. mainland within their range.

According to some assessments, North Korea has succeeded in miniaturizing nuclear warheads. No doubt, the country's nuclear missile development has progressed at a faster pace than anticipated by the U.S. government.

What cannot be overlooked is that Pyongyang has announced a plan, as a grave warning to the United States, to simultaneously fire four Hwasong-12 ballistic missiles to waters around Guam, a Pacific island territory of the United States. It said the plan will be ready by the middle of this month and the personnel will wait for a launch order.

The plan is clearly aimed at keeping in check the U.S.-South Korea joint military exercises scheduled to start in South Korea on Aug. 21. Guam has a U.S. Air Force base where strategic bombers are deployed. If North Korea launches four missiles as planned, it will heighten military tension to a maximum.

Bolster tie-up with allies

The commander of the Strategic Force of the Korean People's Army stated the missiles would fly over Japan, specifically mentioning "Shimane, Hiroshima and Kochi prefectures."

Chief Cabinet Secretary Yoshihide Suga has every reason to denounce the North's plan, saying, "It is obviously an act of provocation and absolutely cannot be tolerated."

Defense Minister Itsunori Onodera expressed the view that firing missiles at waters near Guam could be designated as "a survival-threatening situation" and as such could permit the exercise of the right of collective self-defense.

If it is designated as such, missile interception and protection of U.S. military vessels will be allowed. The government needs to prepare for all possible situations in close cooperation with Washington.

Another worrying matter is that U.S. President Donald Trump warned Pyongyang, saying: "North Korea best not make any more threats to the United States. They will be met with fire and fury like the world has never seen." It is extremely rare for a U.S. president to use such language that evokes nuclear attacks.

His remarks can also be taken to mean that Washington has set the North's new nuclear test and launch of medium- and long-range ballistic missiles as the red line for launching military action. Use of indiscreet and threatening language and actions should be restrained.

U.S. Secretary of State Rex Tillerson has expressed the view that Washington does not take a hostile view of Pyongyang and dialogue is possible between the two countries. Trump must work toward policy coordination within his administration and ramp up cooperation with U.S. allies, including Japan and South Korea.

From an editorial Friday in the Japan News/Yomiuri Shimbun, Tokyo