Iran has built its security on being an oil producing state. Unlike Venezuela, Iran is situated in a region which has been crucial to world trade. Geopolitics dictates that Iran either be pro-active in its stand vis-à-vis challengers, or be subjugated and become a slave satellite of one of the world powers.
Power Rivalry: Saudi Arabia and Iran are traditional rivals. Both have aided opposite sides in the Syrian civil war. Russia sides with Iran, while Saudi Arabia has found American friendship firm. Saudis and Iranians do not see eye to eye on many issues. Iranian attacks on Saudi oil installations are exhibitions of hard power. But actually, such attacks also prove that Iran’s stand is weakening.
The Oil Trade: Iran has been a major exporter of oil. However, its reserves are now being exploited into their second generation. More exploitation would lead to faster depletion. Also, the emergence of Russia as an Oil and Gas exporter has lead to the souring of traditional warm Russo-Iranian relations. Russia does not mind if Iran loses customers to Russian exporters. Recently, a major Russo-Japanese LNG deal was signed. Iran’s customers are definitely moving away. Unless it wants to succumb like Venezuela did, Iran feels it must re-assert itself.
Iran-America relations: The US is loath to see a strong Iran in the Gulf region. Just as North Korea is a threat to US hegemony in East Asia, so is Iran an ever-present threat to US power in the Gulf. Israel is a firm friend of America, as is Saudi Arabia. To the detriment of Iran, Russo-Arab relations have been improving. Iran is also trying to re-ignite its nuclear program. The US sees the future Iranian nuclear bomb with the same alarm as the erstwhile Korean nuclear program.
There, it is inevitable that, one of the players being subdued, the bigger actor (the US) will try to consolidate its position in the region by making the temporary discomforts of the lesser power (Iran) permanent.