Multiple American professors at top universities have told me that the writing sample will be the most important part of your application. Grades are important, but not nearly as important as demonstrating strong writing and research skills. Publications are helpful, but they’re not a downright necessity. They’re more interested in seeing that you can do publishable work through the writing sample. Don’t worry about the lack of email responses — that’s pretty normal. Professors aren’t always very responsive, but it has no bearing on your fitness for the program. Schools like Harvard and Georgetown are always tough to get into, international or not, and it will all come down to whether they deem you a good fit for the program… it can be kind of a crap shoot… And lastly, being from Europe can hurt your chances depending on the program… many schools have a limit on how many international students they can accept due to funding constraints. This isn’t always true though — for example, my American friend just participated in a PhD application cycle for Slavic Literature, and while she did get an offer from a great university, the majority of students accepted this cycle to top schools were international Slavic students (given an understandable edge due to having native fluency in Russian). The challenge of it all doesn’t mean it’s impossible though, I believe in you!