Saturday was supposed to be a turning point in Venezuela. U.S.-backed interim president Juan Guaido was supposed to heroically usher aid into his country as the military abandoned their posts and joined the opposition. Ideally, Maduro would have stepped down, new elections would have been called and Vice President Mike Pence would have been congratulating Guaido during his speech in Colombia on Monday.

None of that happened. Instead, most of the aid remained stuck outside of Venezuela. One truck did make it through and a few border guards defected, but other than that, the military held its ground and enforced Maduro’s blockade, resulting in a stand-off that left four dead and hundreds wounded.

Those events and their anti-climactic results should be a lesson in the simple-sounding promise of U.S. intervention abroad: It’s rarely as easy as it sounds.

But the Trump administration seems determined to finish what it has begun in Venezuela. To that end Pence called for new sanctions freezing U.S. assets of Venezuelan officials loyal to Maduro and asked for international support for regime change.

U.S. allies, at first lending their support to Guaido after Washington recognized him as Venezuela’s legitimate leader, however, have grown increasingly wary. On Monday, even as Pence pledged that all options remained on the table, the EU warned against military intervention and Brazil’s vice president vowed that no attack would be launched from its soil and that it preferred nonmilitary pressure.

That diplomatic isolation presents an added challenge for Washington as intervention from the U.S. without the backing of allies would be seen as heavy-handed manipulation and increase the likelihood that Guaido is seen as a U.S. puppet delegitimizing any power that he claims.

To be clear, the Trump administration is right to support Guaido against Maduro’s authoritarian rule and the suffering that it has brought to Venezuela. As much as Americans would like to see his deadly regime toppled, however, it is critical to remember that manipulating the politics of another nation has rarely worked out as intended.

Saturday’s violence and the resulting increased tensions are clear evidence of that. And U.S. troops marching on Caracas isn't likely to smooth over the already volatile situation.