Much has been written about the Thucydides trap, where the fear of a rising power leads a declining power on the path to war. However, fear was only one of three reasons Thucydides gave for nations to go to war, along with interest and honor. An abundant body of scholarship exists on how nations pursue their rational self-interest. However, less attention has been paid to the matter of honor. The concept of honor in international relations may seem archaic. However, it has proven sufficient to move states to war in the past. For example, it was not fear of Argentine power or vital interest stemming from a few dozen sheep farmers which motivated Britain to defend the Falkland Islands. Thus, it is worthy to consider the importance of national honor at a time when we have a president seemingly intent berating and insulting every nation on the planet.
Of course, most nations will seek measures short of war when faced with the might of the US military. However, this is not to say they cannot inflict an incredible amount of pain on the United States. Mexico, for example, could cease cooperation with border security in the United States, thus allowing drugs, crime, and the occasional good person to flood into the USA unimpeded. Mexico could also dramatically increase its military spending, as historically it has underspent on defense, viewing the US as a guarantor of its sovereignty. However, should Mexico come to view the USA as hostile, which it may well do after the 2018 election, it has the ability to make life quite difficult for the United States. While it won’t have the ability to defeat the United States anytime soon, it won’t have to for a military buildup to harm US interests. By forcing sizeable US troop deployments to defend the Southwestern border from a potential attack, Mexico would harm the ability of the United States to project force elsewhere in the world. Thus, it would be advisable for the President to treat Mexico and other allied nations with respect to avoid a needless confrontation. Unfortunately, he probably won’t.