Windeguy is spot on. My Russian girlfriend just spent three years trying to get a US Visa. she got turned down twice--the first two years in a row with a solid "No." This perplexed me to no end becuase A.) she was able to prove that she had a significant, steady income that went back for three years from day one of living here. and B.) she also had traveled extensively around the world and had the passport stamps to prove it, and C.) she also had a child here enrolled in a private school here (Sosua International school) that costs $650 a month plus+ and had the reciepts from every month, and D.) her rent was significantly more than the school tuition, E.) she had bank accounts with money in them, plus a steady income being deposited every month, etc.
She had crossed all her T's and dotted all her I's. nothing was lacking, but most importantly, she showed plenty of bank accounts with money in them. All she wanted to do was go to Miami for a weekend to go shopping! nothing more. In my book, she was a clear shoe-in for a US Visa.
Wrong. They said, "We're sorry, we cannot give you a Visa at this time." Three years later they gave it to her.
To say it's hard to get a U.S Visa would be an understatement of the century. it's beyond hard. it's beyond frustrating. You'll want to pull all your hair out, then pull thier hair out, then the pull your girlfriend's hair out for making you go through all the bureacracy crap for nothing. However, it turns out, the US embassy aren't that stupid after all...their rules and regulations don't permit you to enter their front door or premises with either a Bazooka or 50 caliber. I know this for a fact, i tried! So, they got that going for them.
In conclusion, the U.S embassy are very cautious, but smart. However, it didn't help that they took one look at me standing beside her at the "Interview window" and decided i was probably bad news. I came to the interview with my girlfriend dressed in my father's Vietnam jacket, military pants and flak jacket. In hindsight, it was probably a bad idea. For one thing, i was sweating profusely at the Interview window, but otherwise calm. i didn't say much, but i did stare a lot. i had a twitch in my left eye when he asked me some questions, but I gave my father's rank and serial number and took the 5th on the rest of the questions.
However, You may find that you have better luck.
FRank