The record is clear. Israel rejected God and His way right from the beginning of their relationship. They not only rejected Him and His way but also became a major vehicle for facilitating the spread of the false ways of the heathen all over the world. Modern Israel has followed the same path as her ancestors. As Israel migrated into and through northwestern Europe and settled into the lands God had set aside for them, becoming wealthy, she has given the world a poisonous cultural brew to drink, influencing them through the power of her example. She has the wealth to enable her people to export it to other nations for their consumption and inevitable emulation.
God calls Israel's sins "fornication" because sexual sins are the most common way unfaithfulness in marriage is revealed to the public. Everybody can relate to it. However, the real spiritual sin behind all these sexual terms is gross idolatry. Israel simply did whatever she wanted to do, whenever and however she wanted to do it. The harlotry implied is clearly the breaking of the terms of the marriage covenant. Her harlotry is unfaithfulness and disloyalty, which are spiritual in nature. Her sin is primarily idolatry, but all other sins are included.
Israelites were unfaithful in conducting business both domestically and internationally, unfaithful in managing God's great, green earth, unfaithful in forgetting who their great blessings came from, and unfaithful in the way they treated one another in their personal marriages.