Reuters
While some of his claims were mocked in the press for how profoundly ludicrous they were - for instance, the allegation that the chemical weapons attack was perpetrated by the rebels on their own people - the former KGB agent did in fact make several objectively true points.
For those looking for the definitive textual analysis of the letter, please see Max Fisher's elegant, line-by-line fact check. For those looking to merely see the objectively true things said in the piece, here you are:
"Relations between us have passed through different stages."
This is clearly true. Since the dawn of the American experiment, relations between the U.S. and Russia have indeed passed through multiple phases. Since the sale of Alaska to the United States in the mid-19th century, the U.S. has had a dynamic relationship with Russia. Russia supported the U.S. in the civil war. The U.S. provided humanitarian assistance during thr Soviet 1921-1923 famine. We've been through a lot.
"We stood against each other during the cold war."
"But we were also allies once, and defeated the Nazis together."
This is also somewhat well known.
"No one wants the United Nations to suffer the fate of the League of Nations, which collapsed because it lacked real leverage."
While absolutely a simplification, this is also by and large the primary reason scholars believe the League of Nations failed.
"[Many religious leaders oppose intervention in Syria,] including the pope."
It's been a couple centuries since popes were enthusiastic about participating in wars in Syria, and Pope Francis isn't an exception. The pope said "War, never again!"
"The United States State Department has designated Al Nusra Front and the Islamic State of Iraq and the Levant, fighting with the opposition, as terrorist organizations."
"After all, after fighting in Libya, extremists moved on to Mali."
Yeah, and they truly screwed up the situation in Mali.
"The law is still the law"
The U.N. charter remains in effect to this day.
"Libya is divided into tribes and clans."
"Poison gas was used in Syria"
Unfortunately, yes.
"No matter how targeted the strikes or how sophisticated the weapons, civilian casualties are inevitable, including the elderly and children, whom the strikes are meant to protect"
Even in some of the most surgical strikes, the U.S. kills civilians. Yes.
"There are big countries and small countries, rich and poor, those with long democratic traditions and those still finding their way to democracy."
"Vladimir V. Putin is the president of Russia."