Sandinista ranks had ballooned during the final weeks of the insurrection with the addition of thousands of untrained and undisciplined volunteers. These self-recruits with access to weapons were the source of considerable crime and violence. By late 1979, the situation was clearly deteriorating, as petty crime mounted and some Sandinistas abused their authority for personal gain. To end the chaotic situation, FSLN combatants were regrouped into a conventional army framework. At its core were 1,300 experienced guerrilla fighters. Most of the remainder were members of the popular militias and others who had played some role in the defeat of Somoza. Cuban military personnel helped to set up basic and more advanced training programs and to advise the regional commands. The new army, known as the EPS, was placed under the command of Humberto Ortega, one of the nine FSLN commanders and brother of Daniel José Ortega Saavedra, the Sandinista junta coordinator.

The Sandinistas announced initially that their goal was to build a well-equipped professional military of some 25,000. Their primary missions were to deter attacks led by the United States, prevent a counterrevolutionary uprising, and mobilize internal support for the FSLN. The strength of the EPS increased steadily during the Contra war in the 1980s. At the time the peace accords for the Contra War went into effect in 1990, the EPS's activeduty members numbered more than 80,000. Supplemented by reservists and militia, the Nicaragua armed forces had an overall fighting strength of more than 125,000.

The build up of the regular army depended at first on voluntary enlistments, but later in 1983 a universal conscription system, known as Patriotic Military Service, was adopted. Males between the ages of seventeen and twenty-six were obligated to perform two years of active service followed by two years of reserve status. Service by women remained voluntary. Mandatory conscription was bitterly resented. Thousands of youths fled the country rather than serve in the armed forces, and antidraft protests were widespread. The unpopularity of the draft was believed to have been a large factor in the Sandinista election defeat in 1990.

Inheriting only the battered remnants of the equipment of Somoza's National Guard, the Sandinistas eventually acquired enough Soviet heavy and light tanks and armored personnel carriers (APCs) to form five armored battalions. The Soviets and their allies delivered large amounts of other equipment, including 122mm and 155mm howitzers, 122mm multiple rocket launchers, trucks, and tank carriers. A mix of infantry weapons employed by the Sandinista guerrillas was gradually replaced by Soviet AK-47 assault rifles in the EPS and eventually among combat elements of the militia as well.

The Sandinistas upgraded the modest air force left by the National Guard after sending personnel to Cuba and East European countries for pilot and mechanic training. The most important acquisitions were Soviet helicopters for battlefield transport and assault missions. Although pilots were trained and runways con310 onstructed in preparation for jet fighters, neither the Soviet Union nor France was willing to extend credits for the purchase of modern MiG or Mirage aircraft. The United States warned that the introduction of sophisticated jet fighters would risk retaliatory strikes because of the potential threat to the Panama Canal. Armed patrol craft and small minesweepers replaced the old patrol boats left by the National Guard, to defend against attacks on harbors and shore installations.

Data as of December 1993