Guaidó's supporters are shipping food aid from Colombia as a political gesture. (The US donated the aid as a political gesture.) Maduro's sent troops to block the frontier bridge to Colombia as a political gesture.

They are equally gestures. Nonetheless, there is a moral difference between giving aid as a political gesture and blocking aid as a political gesture.

It seems this is not, as I believed, the bridge I had used to cross to get to Cúcuta — rather, a new bridge constructed in 2015, which has never actually been used.

The article points out there are grounds to suspect the US is including weapons guns in the humanitarian aid.

Indeed, the US could do that. But it should be possible to check the aid to make sure there are no weapons in it.