To my knowledge, tourist books issue warning about every single country, in one way or another. Most countries have a higher crime rates than Japan, the US is a bummer to get in, security-wise, Mexico is one of the most dangerous countries to drive in. One is always advised to dress modestly in churches, it is a really bad idea to buy property in Spain, and meat in the UK is always over-cooked in restaurants, for fear of germs and other health hazards. Not to mention being attacked verbally by waiters in France. Of course, when you read all of these "advices" as once, it sounds as if Israel is described as a dangerous or unwelcoming place. It is not the case in the overwhelming majority of tourist guides.
Taliban attack police HQ in Kunduz (AP)
from the article: Visit Israel at your own risk, warn many Western countries