There is no way in the world that frum Jews going OTD and marrying Arabs in Israel is more common than American frum Jews going OTD and marrying atheists/Xians.
The chance that a Jewish Israeli marries an Arab is probably less than one in a thousand. Every time it happens there are protests!
The chance that an American frum Jew goes OTD and marries a non-Jew is far, far higher, certainly more than 1/100 and possibly as much as 1/10 or higher, depending on the community.
American culture is so anti-Torah right now, that all it takes is kids surfing on the internet and getting involved in social media and seeing what non-frum young people think these days–which is pure hedonism and knee-jerk opposition to anything religious–that they easily get swept up in the current. I personally know of kids that basically went OTD after being convinced that toeiva “marriage” is right and anyone against it is a hater.
Israeli hard-core leftists at Ha’aretz and such are bad, but Israel is different because everyone knows society is becoming more religious and more “right-wing,” and there’s no stopping it for demographic reasons.
I see no reason to think frum Jews going off the derech is more common in Israel (and I’ve seen no evidence indicating that). Certainly there is the transition to worry about, but at least in Israel it’s easier to be an observant Jew — kosher restaurants everywhere, more or less free public religious schools, it’s normal everywhere to wear a kippah in public and dress tznius, etc. And davening and learning is more meaningful to kids who actually speak and understand the language.