The meddler’s trap denotes a situation of self-entanglement, whereby a leader inadvertently creates a problem through military intervention, feels they can solve it, and values solving the new problem more because of the initial intervention. The inflated valuation is driven by a cognitive bias called the endowment effect, according to which individuals tend to overvalue goods they feel they own. A military intervention causes a feeling of ownership of the foreign territory, triggering the endowment effect.

According to a simple definition from dictionary.com, “meddle” means “to involve oneself in a matter without right or invitation; interfere officiously and unwantedly.” Meddling defines many US foreign policy decisions where the “meddler’s trap” begins with President McKinley.

President McKinley did not set out initially to annex the Philippines. The Spanish-American War declaration—approved in 1898, by the US Senate—allowed the US military to place about 14,000 troops in the Philippines, leading the island chain to be conquered. Here, the mindset (cognitive bias) of valuing what you “own” comes into play. When you value something from conquest, like a nation, then it is hard to let it function on its own without meddling or oversight.