Two US B-1B strategic bombers conducted live-fire drills with South Korean fighter jets over the Korean Peninsula on Saturday.

The drill was a simulated attack on a North Korean missile launcher, and signaled a warning message to the North for test-launching an intercontinental ballistic missile Tuesday.

It is the first time for B-1B bombers to have publicly conducted a drill over the Korean Peninsula.

South Korea and the US forces in Korea fired ballistic missiles into the South Korean waters in a show of force a day after the North’s ICBM test.

President Moon Jae-in warned the North after its ICBM launch that if the North crosses the red line, South Korea and the US may take some action.

North Korean leader Kim Jong-un believes the US will not attack the North to defend the South as long as it can attack the US with nuclear missiles.

But the joint Korea-US exercises show that Pyongyang’s nuclear and ICBM capability, no matter how advanced it is, cannot break their alliance.

The North’s ICBM test has awakened the South to the importance of strong national defense once again.

Pyongyang is expected to keep trying to improve its nuclear and missile program despite sanctions and dialogue offers.

Its sixth atomic bomb test is likely to happen within this year.

The South should strengthen its military might as fast as possible to cancel out nuclear and missile threats from the North.

Pyongyang is able to fire missiles at Guam, Alaska or cities in the South right now.

That is why South Korea should shift the focus of its North Korea policy from missile deterrence to missile defense.

The North reportedly has more than 100 Scud, about 50 Rodong and some 50 intermediate-range missiles.

Despite escalating North Korean provocations, South Korea’s responses were mostly rhetoric. Each time the North conducted nuclear or missile tests, Seoul condemned and warned most of the time. It should have built an effective defense system.

Korea is working on the improvement of its Patriot missiles to intercept short-range missiles. The US has deployed only the radar and two launchers of a Terminal High Altitude Area Defense antimissile battery in Korea. Basically, a THAAD battery consists of a radar and six launchers.

If the North fires missiles at the South, how can it fend them off?

Now it is time to find the answer to the question.

Wishful thoughts that Pyongyang will give up its nukes if the stability of its regime is guaranteed or that it will not drop atomic bombs on the South because they are ethnically the same had better be discarded.

A watertight strategy to defend the nation even when a worst-case scenario becomes a reality is needed.

The first thing to do is to establish an effective ballistic missile defense system.

For now, intercepting missiles in midair is the best way to defend the nation.

Improvement of the current Patriot missile systems should be accelerated. More Patriots should be purchased and deployed around major cities.

The complete deployment of the THAAD battery should be finished as fast as possible. Additional purchase or deployment needs to be considered.

A recent simulation research by the Asan Institute of Policy Studies, a local think tank, found the addition of THAAD batteries with 60 percent of interception success rate made the nation’s missile defense network at least six times more effective than Patriots alone.

It estimated the nation will need at least five to seven THAAD batteries to protect its strategically important areas from North Korean missiles.

According to a Gallup Korea poll conducted July 4-6, 57 percent of Koreans supported the THAAD deployment, with 27 percent opposing it. The support rate went up 4 percentage points from last month, with opposition dropping 5 percentage points.

There are no reasons to delay the complete deployment of the system. Rather, the current situation requires additional systems to be fielded.

Missile defense systems should be integrated as well to ward off missiles more efficiently.

North Korea is developing missiles faster than anticipated.

There is not much time left.