El Salvador has received 238 alleged members of Venezuela's Tren de Aragua gang and 23 MS-13 members from the United States, establishing what analysts describe as an unprecedented model of cross-border incarceration services. The prisoners are now detained in the Central American nation's maximum-security Terrorism Confinement Centre (CECOT), as confirmed by officials from both governments.

The arrangement, first mooted last month during US Secretary of State Marco Rubio's visit to the country, comes with significant financial implications. The US will pay El Salvador $6mn to imprison approximately 300 individuals for one year, with renewal options, according to reports by the Associated Press. For El Salvador, facing a public debt of $31bn (82% of its GDP), this represents a vital revenue stream that President Nayib Bukele said would be making the prison system "self-sustainable."

Further details of the agreement reveal that housing each prisoner will cost around $20,000 per year. Additionally, a US State Department document indicates that $15mn may be allocated to El Salvador to detain additional gang members, expanding the scope of this transnational incarceration deal.

The move occurred despite last-minute legal challenges in the US. District Judge James E. Boasberg reportedly issued an order temporarily suspending the deportations, but they proceeded nonetheless.

The White House rejected claims that officials had defied the court order, with Press Secretary Karoline Leavitt stating the deportees were no longer in US territory by the time the ruling was published on March 15.

"A single judge in a single city cannot direct the movements of an aircraft carrier full of foreign alien terrorists who were physically expelled from US soil," Leavitt said in a statement.

The deportations were executed under the 1798 Alien Enemies Act, a wartime declaration unused since World War II. President Donald Trump invoked the law by claiming the Venezuelan Tren de Aragua gang constituted an "invasion" of US territory, allowing for expedited deportations without standard legal protections.

The CECOT, a $70mn facility opened in 2023 with a capacity for 40,000 inmates, stands at the centre of this initiative. El Salvador is offering this jail to foreign governments, with particular interest from the United States, where annual expenditure on correctional facilities reaches $80.7bn for public institutions and $3.9bn for private facilities. The mega-prison is a key element of President Bukele's successful crackdown on gang violence, which has transformed El Salvador from one of the world's most dangerous countries into one of Latin America's safest.

But the massive detention centre has faced scrutiny from human rights organisations. According to NGO Cristosal, as reported by AP, the facility prohibits visitation, outdoor access, and lack rehabilitation programmes. The organisation has documented 261 deaths in Salvadoran prisons during Bukele's crackdown on gangs. In recent months, the Inter-American Commission on Human Rights (IACHR) has also expressed concern over the conditions of the Salvadoran prison system.

Family members of those deported have contested the criminal designations. "Many turned themselves in to US authorities because they could no longer sustain their economic situation there, but they are not criminals," claimed one relative in social media posts described by BBC, urging individual case reviews.

Venezuela's government condemned the deportations as "criminalising migration" and invoking "the darkest episodes of human history, from slavery to the horror of Nazi concentration camps". It remains unclear why Washington opted to send the alleged Venezuelan criminals to El Salvador for a fee, rather than returning them to their native country, which on March 14 accepted the resumption of repatriation flights, as confirmed by US Presidential Envoy for Special Missions Richard Grenell.

This novel arrangement lays the groundwork for what could become a template for international detention outsourcing. Chilean conservative politicians have already expressed interest in similar arrangements with El Salvador, as documented by multiple regional news outlets, suggesting potential expansion of this model throughout the Americas.

The deal reflects broader shifts in international justice systems and corrections management. Comparisons have been drawn to America's "Prison Valley" in Fremont County, Colorado, where 13 maximum-security prisons have created a localised incarceration economy. El Salvador appears to be adapting this model internationally.

The agreement further strengthens ties between Trump and Bukele, both known for their "hard-line" approaches to crime and immigration. Bukele has actively cultivated this partnership, viewing it as beneficial to El Salvador's economic and security interests.

For the Trump administration, the deal addresses prison overcrowding challenges while signalling a tough stance on immigration and transnational crime. It also aligns with Trump's strategy of building regional alliances with ideologically aligned leaders.

As details of this new model of international incarceration emerge, the arrangement warrants close monitoring from policymakers, human rights advocates and criminal justice experts worldwide. The precedent set by this US-El Salvador deal could remove the stigma from detention outsourcing and reshape how nations approach the practice, notoriously riddled with legal pitfalls, in the coming decades.