Once rock solid, his reliance on his two main allies - China and Russia - now appears increasingly uncertain.
For years, both countries supported Venezuela's socialist-led government politically, financially and militarily - a relationship that began under former President Hugo Chávez, Maduro's mentor and predecessor.
But experts say that backing now seems to be largely symbolic, with statements being given in support rather than concrete military or financial aid.
The Trump administration has said the military build-up and strikes are targeting drug trafficking, and the tanker had been sanctioned.
Experts say China defending Maduro could jeopardise recent diplomatic gains between Beijing and Washington, while offering little beyond ideological alignment.
Beijing has reduced new lending in recent years and is now focused mainly on recovering past loans.
Getty Images Venezuela has purchased hundreds of millions of dollars' worth of Chinese military equipment since 2005. »