Introduction
NATO held its 32nd summit in Madrid, Spain between June 29-30 where the military alliance unveiled its new 2022 Strategic Concept. In the lead-up to the summit James Brooke and Ivana Stradner of the Foundation for the Defense of Democracy (hereby referred to as the FDD authors) joined the debate by writing the following for The Dispatch.
The Baltics ask for a division of NATO troops, between 20,000 and 25,000 soldiers, to be allocated between Estonia, Latvia, and Lithuania…
There is a precedent: For almost 70 years on the Korean Peninsula, U.S. Army bases between Seoul and the Demilitarized Zone have served a “human tripwire” role, forcing North Korean to think twice before invading.
In next week’s Defense Debrief I will argue that NATO should employ the “spider web“ strategy to defend its eastern flank. In this week’s article I will disagree with the FDD authors use of the “human tripwire“ analogy.
South Korean Tripwire?
First, we need to define the concept of “human tripwire”. Professor Dianne Pfundstein Chamberlain described the "human tripwire" strategy as
placing a small number of forces in an area to signal its strategic importance to both a state’s adversaries and its allies
How would these “human tripwires” operate in practice? If attacked the adversary should expect to fight a much larger force as the conflict escalates.
The tripwire force is intended to deter invasion of an ally’s territory not by immediately denying the invader the ability to achieve her objectives, but by guaranteeing that an invasion would entail an attack on one’s own forces along with those of the ally, thus ensuring a dramatic escalation in the conflict.
The FDD authors classified US bases in Korea as “human tripwires”. This would suggest that the U.S. and allied forces in Korea lack the necessary size to handle a conventional attack from North Korea. I do not believe this is correct, Professor Lami Kim argued that while North Korea enjoys superiority in nuclear forces, South Korea possesses superiority in conventional forces.
North Korea’s conventional capabilities significantly lag behind those of South Korea. Much of its conventional weapons are outmoded, and its soldiers are malnourished. North Korea’s defense spending is far lower than South Korea’s. To put things into perspective, South Korea’s 2020 defense budget was $45.7 billion, about 1.5 times North Korea’s entire GDP that year, which was $27.4 billion.
Why does it matter whether or not we classify U.S. forces in Korea as a “human tripwire“? In her book, Cheap Threats, Professor Chamberlain studied events from 1945-2007 where the U.S. issued a threat to change a target country’s behavior. The results of her study challenge the fundamental tenets of the tripwire strategy.
I found that threats fail when they are cheap to issue and to execute because cheap threats do not signal that the United States is highly resolved to prevail over a stubbornly resistant opponent. A target believes that a cheap threat is likely to be executed, but it doubts that the United States will have the willingness to commit substantial resources over a long period of time to secure a brute force victory after the initial application of force fails to change the target’s behavior.
Given the poor state of North Korea’s conventional army, the conventional capability of South Korea, and the size of the U.S. military force in South Korea (nearly 30,000 troops) I disagree with labeling US forces in Korea as a “human tripwire“. “Human tripwires” present a cheap threat which adversaries conclude equals a lack of resolve. While I do not believe the U.S. uses the tripwire strategy in Korea, I do believe NATO currently employs it in Europe.
European Tripwire
Russia’s annexation of Crimea convinced NATO of the need to increase the protection of its eastern flank. NATO created four battlegroups for Estonia, Latvia, Lithuania and Poland to be directed by the United Kingdom, Canada, Germany and the United States respectively. According to the NATO graphic below, the new battlegroups resulted in NATO positioning 40,000 troops (Host - 30,000 / NATO Allies - 10,000) to defend the three Baltic states from a Russian attack.
The U.S. stations nearly three times as many troops in South Korea to defend against a weak North Korea as NATO stations in the three Baltic states to defend against a stronger Russia. To attack Ukraine Putin raised an army of 200,000 soldiers and the armor, artillery, and aircraft needed to support those troops. Historical scholarship mostly agrees that an invading force requires a 3:1 ratio of forces compared to the defense.
By that logic, the Baltic states still remain vulnerable if Putin can raise an army of at least 120,000 for an invasion. While this task appears daunting due to Russia’s current invasion of in Ukraine, one should suspect that Putin holds ambitions to re-integrate all former imperial territories into modern day Russia. A few weeks ago Putin stated that the fight over Finland in The Great Northern War was a fight for Russian territory.
Peter the Great waged the Great Northern War for 21 years. It would seem that he was at war with Sweden, he took something from them. He did not take anything from them, he returned (what was Russia’s)
Despite uncertainties regarding the length and outcome of Russia’s invasion of Ukraine, one should assume that Putin can raise the necessary forces for an invasion of the Baltic states if given enough time. Luckily for NATO, the U.S. Marine Corp demonstrates how one can defend against a modern armed force in a cost-effective manner. In next week’s article I will demonstrate how the U.S. Marine Corp’s innovative tactics to defend against China should teach NATO to build “spider webs” instead of “human tripwires”.