What are the political obstacles to the resurrection of the Nabucco pipeline from Iran?

As already reported by another question the Russian state-owned energy company Gazprom has ceased gas deliveries to Poland and Bulgaria. The problem with alternative supplies is that they are few and some were killed in the past like the Nabucco pipeline. If I understood correctly the official reason to kill the project was commercial, but probably there was political pressure on the background. Given the current situation could the project be resurrected?

Here I'll split my question in two separate questions because the international relations of Iran and Azerbaijan are much different and require different answers. In this question I would like to know what are the political obstacles to the project of a gas connection from Iran. There could be different options if the European countries decided to take into account or ignore the American sanctions, I would like to know both.