In November of 2019, nearly three years into his first term as US president, Trump was declaring his desire for the US military to attack in Mexico. Trump expressed his desire to, with the approval of Mexico's president, "wage WAR on the drug cartels and wipe them off the face of the earth." But, this action did not materialize as Mexico President Andrés Manuel López Obrador was not accommodating to the idea and Trump became focused on his own reelection campaign.

When then out of office for four years, Trump appeared not to relent on his desire for war on cartels in Mexico. Indeed, the expression of this desire made it into his hour-long November 15, 2022 speech at Mar-a-Lago in Florida in which Trump revealed his presidential agenda for a return to the White House. "We will wage war upon the cartels and stop the fentanyl and deadly drugs from killing 200,000 Americans per year," declared Trump. On this issue, Trump was not an outlier in the Republican presidential primary. Most other prominent candidates in the primary were also beating the drum for a US war on Mexico.

In the first few weeks of his presidency, Donald Trump and his administration have been taking steps that appear to be on course toward a US war on Mexio.

Upon being sworn into office on January 20 with Republican majorities in the House of Representatives and Senate, Trump wasted no time in setting up prerequisites for a US war on Mexico. That day, he signed his "Declaring a National Emergency at the Southern Border of the United States" executive order.

Cartels, along with "criminal gangs, known terrorists, human traffickers, smugglers, unvetted military-age males from foreign adversaries, and illicit narcotics that harm Americans" were identified in the executive order as having overrun the US-Mexico border and contributed to the situation where "America's sovereignty is under attack."

In the executive order, Trump called for literal militarization of the US-Mexico border, stating that "it is necessary for the Armed Forces to take all appropriate action to assist the Department of Homeland Security in obtaining full operational control of the southern border." (The border was already "militarized" in a more general sense given that, working with the border-industrial complex, the US government has been long operating heavy-handed control at the border and for many miles with the border largely immune from liberty-protecting restraints applicable elsewhere in America.)