Final deliveries blocked by US actions
The final deliveries of fuel have been disrupted by US threats to sanction the individual boats carrying the gasoline. Reportedly, these threats have halted the final delivery of all the gasoline although it would seem that at least two or three of the vessels have already delivered their oil. All along there were fears that the US might actually intercept the tankers as there are US military vessels near to Venezuela. However this did not happen.
The ships are Greek-owned, and banking sanctions could be problematic for them as well as the fact they would be unable to transact business with the US. The US could also interfere in any international banking transactions as the US has considerable control over SWIFT.
US uses SWIFT to enforce sanctions on countries such as Iran and Venezuela
The US has enough influence on SWIFT that it can force SWIFT not to allow countries it sanctions to use SWIFT services. As a result such countries need to use other methods of finance. The gasoline sales by Iran are paid for in gold that was flown to Iran. The US has sanctioned a Chinese company that it claims had facilitated the gold shipment.
The extra-territorial application of US sanctions
Theoretically US sanctions should apply only to business those sanctioned try to carry out with the US. However, the US uses its financial clout in institution such as SWIFT to enforce its sanctions outside its territory. Also many countries and companies do considerable business with the US even if they themselves are not sanctioned the US can threaten them with cutting off business dealings with them should they not obey the US sanctions.
The EU is developing its own international finance system that will help EU countries to get around US sanctions. Many countries also are beginning to avoid the use of US dollars in trade and using other currencies in order to depend less on US influenced international financial systems. Some countries are even trading goods for other goods.
US decided upon intervention a bit late
The US had been issuing threats against the tankers ever since the deliveries began but did not interfere until now when much of the gasoline is already delivered. There were US ships in the Caribbean and the US was threatening to do something aggressive. But so far they have carried out no interceptions, so it is unlikely that there will be any direct interception of an Iranian tanker. However a recent report claims that two of the Iranian tankers have scrapped their delivery plans: “Two Liberian-flagged, Greek-owned ships that “were en route to Venezuela carrying Iranian fuel, scrapped their deliveries after the U.S. threatened sanctions,” a senior U.S. official told Fox News.”
The US has been supporting a coup attempt by Juan Guaido against the presidency of Nicolas Maduro. So far all US attempts have failed.
However US envoy Elliot Abrams warned all nations that allowing Iran to sell gasoline to Venezuela is a “very dangerous transaction to assist. They do not suggest that trying to disrupt a peaceful trading transaction between two sovereign nations is not only dangerous but against international law. The US has already sanctioned a Chinese company as mentioned just for facilitating this transaction. The US wants to police the world under rules it makes even when these rules are against international law and peaceful trading relations between sovereign countries.
UPDATE: More recent report claims that the fifth tanker has entered Venezuelan waters: https://www.presstv.com/Detail/2020/06/02/626573/Iran-Venezuela-tanker-Clavel-sanctions-
