Because Google Translate only gives so much nuance and understanding, here is how Fox News covered the op-ed:

But in his column, titled “My Brother Obama,” the older Castro all but mocks the U.S. president’s efforts. He goes over crucial sections of Obama’s speech line by line, engaging in an ex-post-facto dialogue with the American president with pointed critiques of perceived slights and insults, including Obama’s failure to give credit to indigenous Cubans and Castro’s prohibition of racial segregation after coming to power in 1959.

If you can read Spanish or stomach the touchy, disjointed word soup of Google Translate, the original article is here. Although it can be hard to parse at times, the entire letter makes sense on the whole. Castro dedicated his writing in the official Communist newspaper of Cuba’s government to reminding Obama and the American people that there has been too much animosity and violence in the past to just become pals now. This passage stands out as understandable and evocative:

In 1961, just two years and three months after the triumph of the Revolution, a mercenary force with cannons and armored infantry, equipped with aircraft, was trained and accompanied by warships and aircraft carriers in the US, raiding our country. Nothing can justify this premeditated attack that cost our country hundreds of killed and wounded. Pro-Yankee Brigade assault, nowhere has there could have evacuated a single mercenary. Yanks warplanes were presented to the United Nations as rebels Cuban teams.

The hand of friendship Obama tried to extend just got slapped away by an 89-year-0ld man who said, simply, “We don’t need the empire to give us any presents.”

This is the icing on the cake after all the negative press President Obama got here at home.  During the terrorist attacks in Belgium, he spent 51 seconds on the tragedy, then went to a baseball game with Raul Castro  where he laughed, waved, and did the wave in great delight.  Later, he stood before a wall mural of Che Guevara  for a memorable  photo op.  

Next, he was off to Argentina where the photo op was dancing the tango.  He is reported to have said, “She insisted!”  What are the Secret Service for, Mr. President?”