The idea of South Korea developing nuclear weapons is reaching critical mass, if you’ll excuse the pun. Surveys show as much as 70 percent of the public now in favor. There has also been plenty of commentary on why it’s necessary: North Korea’s growing arsenal, China’s rise, and the United States’ perceived increasing unreliability. The feedback buzz between public opinion and commentary has grown so much that the issue became a presidential campaign topic.

However, just because something is popular and there are good reasons for it doesn’t mean politicians will deliver it. Both sides of politics have their reservations. The left sees it as harmful to relations with Pyongyang and at odds with the goal of denuclearising the north, while those on the right fear alliance pushback, damage to exports, and weakening of relations with China.

But the more fundamental obstacle is that going nuclear would require consistent unity of national purpose: an executive must decide to do it, a legislature must pay for it, and the apparatus of government must facilitate it. These efforts must then be sustained long enough to make it happen. But unity is a typically scarce commodity in South Korean politics, and is certainly nowhere to be seen now.  Politics has been nothing if not turbulent over the past 10 years.

The country remains relatively functional and maintains bipartisan focus on certain policy approaches. Still, embarking on something new and ambitious, such as a nuclear weapons program, is different to merely keeping on. It requires a novel and sustained confluence of ideological currents.

In South Korea, North Korea is an ideological fulcrum. The extreme right wants to liberate the north at the risk of war, while the furthest left wants the north’s regime to reign over the entire peninsula. Politics happens in the middle. The left wants to accommodate the north’s preferences on the way to cooperative unification, while the right insists that the north must accommodate the preferences of the south—including denuclearisation—if cooperation is to proceed.

The left now holds both the legislature and the presidency. Security plays a crucial role in outreach to the north, as it provides the South Korean public with the confidence needed to pursue cooperative peace, or even unification. But those on the left believe that security can come from the US alliance and from South Korea’s considerable conventional capabilities. In their view, nuclear weapons are not only unnecessary; they would disrupt engagement with Pyongyang and derail the agenda internationally.

The right doesn’t get to decide matters of state anymore. But even if missteps by the left gave it that power in the future, it would balk at nuclearisation. For the right, the US alliance is central to protecting the south from the north. And while some parts of the Trump administration may be open to the idea of South Korea going nuclear, an effort in that direction would face considerable alliance headwinds. Also, the fear of damage to South Korean exports and relations with China means it’s not a serious option. To this side, trying to convince the US to do something, such as nuclear sharing, is a better option.

Given that developing nuclear weapons is a non-starter, why all the smoke if there is no fire? The short answer is that it promises a solution to very real problems in the eyes of those in the centre, for which the left and right lack answers. Nukes would allow South Korea to stand up to bullying from increasingly powerful and assertive North Korea and China, while also greatly reducing dependence on a capricious US intent on increasing South Korea’s involvement in checking China. But as popular as it is, there is no broad constituency to make it happen, and certainly not one strong enough to sustain it when that nice-in-theory idea meets geopolitical realities.