Despite North Korea's flashy displays of weaponry, South Korea's military is still seen as having qualitative and technological advantages.
But Seoul's foundering effort to modernize its forces over the past two decades means it may not be equipped to fend off a North Korean attack.
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In the dead of night on January 14, North Korea held yet another military parade in Pyongyang.
It was essentially a repeat of the military parade in October, which was described as a "new look" for the Korean People's Army (KPA), showcasing new tanks, missiles, armored vehicles, uniforms, and other military equipment.
The parades are likely to compound already significant fears among South Koreans about the strength of their military.
According to a 2020 survey by the Korean Institute for National Unification, 40% of South Koreans believe North Korea's military is stronger than the South's, while just 32% believe that South Korea's military is stronger.
While that may come as a shock given the South Korean military's qualitative and technological advantages, it stems from very real problems it faces in its demographics, the pace and scale of its modernization, and its funding.
Together, these are serious issues for South Korea's military, especially its Army, and could seriously affect its ability to fend off an attack from the North.
Defense Reform 2020
The South Korean military's current predicaments were foreseen. In 2005, the South Korean government, noticing the country's declining birth rate, enacted a plan to downsize the military, well over half of which is made up of draftees.
The intention was to replace it with a much more technologically advanced force - a quality-over-quantity model similar to that adopted by Western militaries during the Cold War.
To that end, the government created the Defense Reform Plan 2020 (DRP). It called for a reduction from about 682,000 troops to 500,000 by 2020, with almost all of the cuts coming from the Army. Additionally, the length of required service was reduced for each branch.
It also called for an annual increase to the defense budget of up to 10% to replace aging hardware with modern systems.
At the time, South Korea's armored force was made up mostly of early Cold War-era M48 tanks, while its Air Force relied on F-4 and F-5 fighter jets. These were to be replaced by modern K1 and K2 tanks and F-16, F-15, and eventually F-35 fighters. The Navy was also expected to get a number of new vessels, including submarines and amphibious assault ships.
Budget cuts and technical issues
The plan ran into financial trouble almost immediately.
The budget increases never hit the 10% mark, and the military was also forced to increase monthly wages for draftees to address the growing unpopularity of conscription. Volunteer wages were also increased in order to attract badly needed full-time professionals. Neither of these additional costs were part of the original plan.
To make matters worse, technical issues caused cost overruns on the K2 program, and North Korean attacks on South Korean islands in 2010 forced the military to invest more in its Marine Corps and in preemptive and retaliatory measures.
These unforeseen costs, along with other domestic political priorities, forced cuts to the reform plan, mostly to research and development and acquisition.
The original order of over 1,000 K2 tanks was reduced substantially; about 260 are in service today. Only two of the planned nine domestically built KSS III submarines have been launched, and neither have been commissioned.
An Army left behind
South Korea's military is now one of the most modern in Asia, but most of the modernization funding that has arrived has gone to the Air Force and Navy.
The Air Force now has over 100 F-16, 59 F-15, and 24 F-35A fighter jets. The Navy operates 17 advanced guided-missile destroyers and frigates, one Dokdo-class helicopter carrier (with another on the way), and a number of capable submarines.
The shortages have been so bad that an Army deployment to the UAE had to borrow equipment from special forces units.
The Army is also expected to take all of the manpower cuts. The current defense reform plan, dubbed Defense Reform 2.0, shrinks the Army from 463,000 troops now to 365,000 in 2025.
The Army's "domination" of the South Korean military "has been largely overthrown," Dr. Bruce Bennett, a senior defense analyst at the RAND Corporation, told Insider.
"All of the manpower has been coming out of the Army, and yet the equipment acquisition has favored the Navy and the Air Force," Bennett added.
The idea is that the Air Force's and Navy's new and advanced hardware, used in support of ground forces, will make up for shortcomings. But most of the likely combat scenarios on the peninsula involve North Korea making widespread tactical use of nuclear weapons. (North Korea is also expected to deploy chemical weapons.)
South Korean Air Force and Navy assets are largely concentrated in a few areas, leaving them extremely vulnerable to those weapons. They could be largely destroyed in the first few hours of fighting.
"If you're in a big war, those things are dead very quickly." Bennet said. "And the hordes then come running South."
A larger enemy
The threat is similar to what NATO commanders faced from the Soviets along the West German border during the Cold War - an enemy targeting important bases and cities with nuclear weapons, followed by waves of soldiers rushing to occupy what is left and declare victory.
If that were to happen in South Korea, it would largely fall to the Army to fend off the onslaught. And while the South Korean Army is getting smaller, North Korea's military, the KPA, will be much larger.
Current estimates place the KPA at around 1.28 million troops, with 1.1 million ground forces, and a reserve estimated to be as large as 7.6 million, compared to South Korea's 3.1 million reserves.
North Korea's military includes a roughly 200,000-man Special Operations Forces branch, which has likely received most of North Korea's conventional modernization efforts and would likely spearhead any invasion.
The overall quality of the KPA is unknown, and full-scale fighting on the Korean Peninsula would involve the 28,500 US troops stationed in South Korea, possibly including American nuclear retaliation.
But with North Korea's ability to destroy the airfields and ports that would be used to deploy reinforcements with nuclear weapons, combined with its intention to build up its intercontinental and submarine-launched ballistic missiles to be able to reach the US mainland, the South Korean military may not be able to rely on the American cavalry arriving to save the day.
To many, then, the challenge for South Korea is modernizing all of its branches while maintaining the large force needed to fight off the KPA.
"The character of the investment has been more, 'how to we maintain stability in peacetime and prevent provocations?' than it has been, 'how do we maintain the ability to fight and win a war, and convince [North Korea] that if they start a war they are going to be defeated?'" Bennett said.