As he worked his way through an inspection at the airport, a member of the revolutionary guard, a young man from their neighborhood, recognized him.
"Julito, where are you going?" he asked.
Julio Castro went cold.
"I'm going to the United States," he replied.
"And your father knows that?" the man asked.
"Yes," he lied.
The guard paused, weighing the likelihood of Julio's response.
"Have a good trip," he said.
Ten months after his arrival, on Oct. 14, 1962, a U.S. Air Force U-2 spy plane flew over Cuba and took photographs of Soviet missile bases under construction on the island. Several U.S. officials argued for an immediate invasion of Cuba, but Kennedy doubted that was the best approach.
Ninety miles away, Jose Castro received orders to help guard a Soviet base in a wooded area; while he was told there were missiles inside, Castro never saw them himself. He was assigned to stand in the trenches outside, and could see the Soviets enter and leave the base.
"I thought they were rockets to defend the country, not attack," he says.
On Oct. 22, Kennedy went on television and informed Americans of the impending nuclear threat. Any attack from Cuba in the Western Hemisphere would require "full retaliatory response upon the Soviet Union," he said.
Julio Castro, in Miami, watched in anticipation. He had already agreed to participate in Operation Mongoose, another CIA plot to remove Fidel Castro and the communist regime from power. As the missile crisis unfolded, he was awaiting his orders to be sent for bacterial, chemical and nuclear training at Fort Knox in Kentucky.
"My goal was to secure this nation," Julio Castro says. "That was the number one goal. Secure the nation and then try to liberate my brother."
As the crisis escalated, the U.S. prepared for war. B-52s and intercontinental ballistic missiles were prepared to launch at a moment's notice. Soviet and U.S. diplomats went back and forth, seeking a peaceful solution. Finally, on Oct. 27, Kennedy agreed to remove missiles in Italy and Turkey in exchange for the Soviets dismantling and removing the nuclear weapons in Cuba.
Jose Castro was sent back to the factory, where he had continued working, not yet a full member of the military. Julio Castro was shipped the next month to Fort Knox, where, even after the crisis was averted, he worked on Operation Mongoose and hoped to overthrow the communists.
Neither knew how close he had to come to fighting against his brother.
Jose Castro spent 30 years in the Cuban military. His mother and two sisters left the island and joined his older brother in the United States during that time.
He wasn't allowed to communicate with them, under a rule he could not have contact with the "enemy."
Everyone in the United States was considered an enemy.
"My family is not the enemy," he thought.
Still, he knew vague details of their lives. His mother kept in contact with his wife, and sent him One A Day vitamins that he took for decades, even when he was sent to Angola. (Cuban troops were used to bolster the African country's then-communist government against rebels for more than a decade beginning in the mid-1970s.)
When his military service was over, Jose Castro entered the civilian workforce. It was there that he began to see another side of the revolution. He didn't have the benefits given to members of the military anymore - food and vacations for his family and rides to work. He and his family lived in a modest apartment with furniture his mother had bought in the 1950s.
In 2004, more than 10 years after retiring from the military, Jose Castro was granted permission to leave the country.
His older brother picked him up at the airport in Miami.
They hugged each other and cried.
"Welcome to the land of liberty," Julio Castro said.
In some ways, Jose Castro grew up to be more like his big brother than he might have known. Both served in the military and both became civil engineers. These days they even work on projects together.