[ihsw]

There are some grammatical and capitalization errors, and numerous comma splices (stringing similar sentence fragments together in an effort to form a coherent statement). There was also usage of very short sentences in repeated succession.

Those are mostly stylistic issues but they're indicative of non-native grasp of the English language.

Furthermore it's clearly written by someone with enough capability to express themselves eloquently and succinctly, but as mentioned it's clearly non-native.

[sytelus]

That's very interesting. Any resources/research that you know about on how to identify non-native writing?

[idProQuo]

Not the same person, but I've found that learning other languages (and making mistakes in other languages) makes you attuned to what kinds of mistakes happen when speakers of that language learn English.

Just off the top of my head, Russian doesn't have articles. A Russian learning English is more likely to confuse definite and indefinite articles than a speaker of a Romance language.

I've been learning Thai and teaching English in Thailand. Thai has no articles, no tenses (in the way we think about them) and a simpler syntax with many prepositions and other "small words" omitted. When they start learning English, they often omit too many words and don't conjugate anything, so a sentence like "I don't have any pencils." becomes "No have pencil".

[sesm]

Of course, Putin's speechwriter is likely to be Russian.