President Donald Trump hasn’t minced words in his justification for the raid and capture of Venezuelan president Nicolás Maduro: he wanted to “take back the oil” that was nationalized by the Venezuelan government. Trump, who promised to fulfill Big Oil’s wishes in exchange for campaign donations, told reporters over the weekend that he met with “all” of the American oil companies before the raid and that “they want to go in so badly.” Such claims have led Senate Democrats to launch an investigation into these communications.

But even as their stocks ratcheted up in the wake of the raid, companies like ExxonMobil, ConocoPhillips, and Chevron are denying any involvement or advance notice of the invasion, albeit under the cover of anonymity, and industry sources are saying that Big Oil is actually hesitant to make the expensive and risky investment in Venezuelan oil infrastructure.

So what does Big Oil really want from Venezuela? How does the situation compare to past wars fought over oil? And what does it mean for the rest of us?