@turkay1-- You're absolutely right. Pieces of the Gates of Ishtar, which were excavated from Iraq, is now in Museums in Germany, Turkey, US, Canada and Sweden. And Iraq is making a claim on them and asking for the artifacts to be returned but has not succeeded until now.
It's not really anybody's fault that this happened though. Until the 1930s, Iraq didn't have any laws on the ownership of excavation. In fact, before the 1930s, half of all artifacts excavated from Iraq were given to those who discovered them. And of course, those discoveries were made by foreign archaeologists. So it's not surprising that whenever a new piece was found, it was taken out of Iraq to whatever country the excavator came from.
I do agree with you that it's nicer to see historical artifacts in the land that they were discovered. But on the other hand, all countries who have pieces of the Ishtar Gate are preserving it rather well. Not to mention that not everyone has the chance to visit Iraq and more people can see it when it's located in several places. I guess we'll see how things will develop after this.