Talk of redeploying US tactical nuclear weapons, which were taken out of South Korea in the early 1990s, is gaining momentum in both the US and South Korea. The idea has considerable merit.

First of all, keeping nukes ready to strike back at the North, which now is believed to be on the verge of possessing nuclear-tipped missiles, could be one of the most effective deterrents to the rogue regime. A balance of terror is needed urgently.

Reintroducing US tactical nukes will also strengthen Washington’s commitment to South Korea’s security. There had been lingering concerns about US President Donald Trump’s isolationist policy and some raised doubt about US readiness to hit back North Korea in the absence of direct threat to the US mainland.

A decision -- or even only consideration by the allies -- to station US nukes here will also impose strong pressure on China and Russia, which often leave loopholes in the UN-led sanctions and other international efforts to stop the North’s weapons programs.

Both China and Russia wouldn’t like US nuclear weapons in their neighborhood. Besides, US nukes in South Korea could also encourage other countries like Japan and Taiwan to seek nuclear armament.

If one looks at China’s vehement protests and retaliations against the deployment of a US missile shield system in South Korea, it is easy to guess how seriously China would take a move to bring US nukes into the South. In other words, South Korea and the US could use the issue itself as leverage in pressing Beijing to play a greater role in reining in the North.

Pressure on China -- and Russia as well -- has become all the more important because the UN adopted a watered-down sanctions resolution against the Pyongyang regime. The US, which had pushed an oil embargo, for instance, had to settle for a compromise with China, only setting limits to exports of oil and petroleum products to the North.

Seeing limitations to UN-led sanctions, an increasing number of politicians, experts and general citizens in both the US and South Korea are joining the call for stationing US tactical nuclear weapons here. The North’s two intercontinental ballistic missile tests in July and the sixth nuclear detonation with what is believed to be a hydrogen bomb early this month fueled talk of rearming US forces here with tactical nuclear weapons.

In fact, before the North’s latest nuclear blast, the general sentiment in the US was negative toward deploying nukes in the South. US National Security Adviser H.R. McMaster warned as recently as August against its negative effect on nonproliferation in Northeast Asia, and US commanders in South Korea had also made clear that they did not support the proposal.

Over the weekend, however, NBC reported that Trump’s security aides discussed the option of redeploying tactical nuclear weapons to South Korea. The report is a reminder of what Trump said during his election campaign -- that he might support allowing South Korea and Japan to develop nuclear weapons for self-defense.

Sen. John McCain, a heavyweight lawmaker who chairs the Armed Services Committee, added weight to the NBC report as he called for a “serious consideration” of the proposal.

In Korea, the conservative opposition Liberty Korea Party is at the forefront of the call for stationing US nukes in the country. It has started a petition and plans to send a letter to Trump and dispatch a delegation to the US.

The party’s moves may well have political motives to recoup its strength and rebuild conservative support after the ouster of Park Geun-hye and defeat in the presidential election. But the fact that the latest public opinion survey found that 68 percent of Koreans support the reintroduction of US tactical nuclear weapons gives enough ground to the party’s endeavors.

Both Cheong Wa Dae and the ruling party insist that deploying US nukes here would only forfeit the ground to demand North Korea to abandon nuclear weapons and damage the global nonproliferation regime. But the 1992 South-North denuclearization agreement has apparently become worthless and the North’s nuclear menace has become an imminent -- not a potential -- threat to our security.