I've read some detailed discussions from people in the industry explaining how blockchains don't help. And I've read some very high level, breezy assertions from people outside the industry asserting that blockchains can help (although they never spell out how, exactly).

As far as I can tell:

1. There's a pretty big issue with containers having the wrong contents (eg, counterfeit items loaded initially, or contraband added during transit). Current solutions are focused around physical security, seals, locks, etc., but it's fairly easy to bypass and forge these physical measures.

2. There's no real issue with tracking containers. We don't always know what's actually in them, but we know really well where they are and what's meant to be in them.

3. There's some efforts to try and replace the electronic systems for tracking where they are and what should be in them with blockchains. But as above, that's the bit that's currently working fine.

Not needing to trust middlemen is a good goal, I just don't see how tracking containers on blockchains reduces my need to trust middlemen. When Customs seizes the container at the border and finds someone has added 100kg of cocaine to the container, how does the blockchain prove who jimmied the lock open and then replaced the tamper seals?

This, a thousand times _this_!

I've worked in shipping for decades. There is no problem with BOLs magically changing with no traceability (which blockchain could solve, I guess, if that problem existed?). There is no problem with checking that the seal on a box at arrival is the same seal that was on the box when it departed.

The only viable purpose I've heard for blockchain is quasi-anonymous decentralized trust negotiation. This purpose doesn't match any real-world use case in shipping. A shipper doesn't want to ship product from an anonymous untrusted producer and no carrier wants to carry goods from an anonymous untrusted shipper.

Blockchain won't stop companies from misdeclaring hazardous (but otherwise legal) goods[1], it won't stop traffickers from misdeclaring illegal goods (or smuggling illegal goods among legal goods)[2], it won't stop trucks from running overweight[3], it won't stop ships from being misloaded[4]...

---

[1] https://en.wikipedia.org/wiki/MV_Hyundai_Fortune

[2] https://www.freshplaza.com/article/9295962/cork-cocaine-valu...

[3] this sort of thing doesn't usually make the news so I don't have a link

[4] https://www.shippingandfreightresource.com/one-apus-containe...

Trust is a lower energy state than distrust. I find it unlikely that society wants to incur the massive expensive of climbing that trust gradient for no benefit.

Any society that adopts trust will be able to compete very well against a society of no trust.

Thst is my conjecture at any rate.

And, more importantly, a blockchain provides a trustless data store. Why can't I just trust myself to keep the data?

"shit in, shit out" is still the working principle. I don't see why the middlemen should make true statements, if that's not in his interest after all. Instead he will just enter wrong information, which will then become "correct" information, "because it's on the blockchain!!11".

Are the middlemen competing with each other to change the supply chain tracking information after it's been recorded in a system over which the purchaser has no control? If so, then maybe blockchain could help with that specific risk. But it can do nothing to prevent middlemen from putting fraudulent information into the record in the first place.