Heavier British casualties and Stalin's channeling of Polish POWs into Soviet sponsored "Free Polish" units leads to a man-power shortage for the western allies. Mexico, Brazil, Cuba, and Colombia parlay this crisis into gaining economic and military aid from the United States; the FDR administration agree to this as part of the "Good Neighbor" policy.
Objections and skepticism from the U.S. military are over come when it is agreed that all latin units will be trained, organized, and outfitted to U.S. Army standards.
Cuban, Colombian, Mexican, and Brazilian troops participate in the ETO while Mexico and Brazil also send smaller numbers of troops to the PTO. All are counted as part of the victorious "combatant powers" at the end of the war.
With the formation of NATO all four countries are founding members of NATO. (All also send at least some combat troops to fight in the Korean war).
All four latin nations receive significant economic benefits from their membership in the western alliance leading to them having much stronger economies than our timeline.
By the early 1980's the Latin American members of NATO have the following troop commitments.
Brazil:
(Peace time commitment)
deployed to Italy: 1 Mech. Infantry Div, 1 Armored Brig, 1 ACR.
(War time commitment) 1st Brazilian Exp. Corps HQ, 1 Armored Div (2 round out Brigades + forward deployed brigade), 1 Mech. Infantry Div. 2 Motorized Infantry Divs. 1 ACR, 1 Attack Helicopter Brigade, 1 Portuguese Mech. Brigade
To the NATO Med. Mobile Force: 1 Airborne brigade, 1 Airmobile Brigade, 1 Marine Division, 1 Lt. Infantry Division, 1 Motorized Cavalry Regiment, Special Forces Group.
Mexico:
(Peace time Commitments)
Deployed to Germany: 1 Mech. Infantry Brigade, 1 Armored Brigade, 2 Motorized infantry Brigades, 1 MCR.
Deployed to Italy: 1 Mountain Infantry Brigade
(Wartime commitment)
Germany: Mexican Army Europe Corps HQ, 1 Armored Div (2 round out brigades + deployed brigade), 1 Mech. Infantry Division, 2 Motorized Divs., 1 MCR, 1 Attack Helicopter Brigade,
Italy: 1 Mountain Infantry Div
NATO Mobile reserve: 1 Airmobile Brigade, 1 Airborne brigade, 1 Marine Regiment, Special Forces Battalion.
Cuba:
(Peace time Commitments)
Germany: 1 Mech. Brigade, 1 Armored Brigade
(Wartime commitments, attached to American IV Corps) 1 Armored Brigade, 1 Mech Brigade, 2 Motorized Brigades.
Nato General Reserve: 1 Airmobile Brigade, 1 Airborne Brigade, Special forces Battalion, Marine Regiment
Colombia:
(Peace time commitments)
Italy: 1 Mountain inf. Brigade.
(Wartime commitments) 1 Mountain Inf. Div
NATO General reserve. 1 Lt Infantry Div, 1 Airmobile Brigade, Special Force Group.