Trade finance is possibly the busiest space in enterprise blockchain today. And while the people behind the different platforms may say they're not in competition, that's not how it looks from the outside.

Announced Tuesday, NatWest, a part of the Royal Bank of Scotland, has joined Marco Polo, the consortium started by enterprise blockchain startup R3 and trade finance specialist TradeIX. The addition of the U.K.'s third largest bank brings the total number of institutions in Marco Polo to 10 and follows a $16 million funding round for the consortium.

But the news also comes on the heels of the recent announcement that We.Trade, a rival trade finance blockchain platform built on Hyperledger Fabric with nine banks on board, has gone live. A spokesman for HSBC, which is working closely with We.Trade, said that the platform executed 10 transactions in the last week.

Marco Polo, meanwhile, is still in the pilot phase and is expected to enter production in the fourth quarter.

As such, the NatWest announcement points to a fault line emerging in this sector, with some banks choosing the faster-to-market but more narrowly focused We.Trade and others going with the more ambitious, but consequently more deliberative, Marco Polo.

Notably, We.Trade is a private legal entity, which has picked off a particular market segment – trade finance for small- and mid-size enterprises (SMEs) in Europe. By contrast, Marco Polo has a much grander vision for a "universal trade network" (UTN), but as a consortium, it can only move as fast as its members.

Still, NatWest specifically cited Marco Polo's focus on standards and interoperability with other platforms as its reason for going with the consortium.

Richard Crook, the head of emerging technology at NatWest's parent company, RBS, told CoinDesk:

NatWest joins BNP Paribas, Commerzbank, ING, Standard Chartered Bank, Natixis, Bangkok Bank, SMBC, DNB and OP Financial Group on the Marco Polo platform.

The consortium, Crook said, "worked hard to define a decentralized open ecosystem in which all parties can openly and evenly participate."

The argument for Marco Polo's approach to trade finance on the blockchain is that while development may take a bit longer, ensuring that the new systems can talk to each other is necessary if this technology is to fulfill its promise of removing friction from global trade.

As it stands, there is a mishmash of platforms and protocols, which some domain experts fear could perpetuate silos.

Oliver Belin, CMO at TradeIX, said that banks today must try to avoid a situation where they work with other fintech players and platforms, as well as having an application developed in-house, and while also trying to work with other banks. R3's Corda, he said, avoids the problem of multiple solutions.

"I think many people are quite surprised that all these blockchain trade finance platforms cannot communicate between each other," said Belin. "Most people – even some banks – think We.Trade can share information with other Hyperledger projects or networks, or even with Marco Polo, which is not the case at all."

That said, Marco Polo says its technology will be seamlessly interoperable with the other main trade finance platform built using R3, known as Voltron.

Sophie Wiberg Holm, project lead at R3, said Marco Polo and Voltron complement each other nicely and are working together closely on things like standards for invoices or purchase orders and allowing for trade assets to be shared between different applications. She also said Corda-based trade platforms can interoperate with the likes of B3i, the insurance distributed ledger technology (DLT) consortium.

"We can't do that without thinking this far ahead and many blockchain solutions today are not solving the issue," she said. "What we want to achieve with a DLT is eliminate these digital silos that appear today."

In the view of Crook at RBS, We.Trade has gone for the traditional platform play and created a single centralized business model over a closed, private cluster of Fabric nodes.

"We are disappointed that we.trade has moved in this direction," Crook told CoinDesk. "It reminds us of the Time Warner-AOL merger in the late 90s where Time Warner believed by purchasing AOL they would own the gateway for most U.S. consumers to the 'internet.'"

On the other hand, We.Trade, which currently comprises Deutsche Bank, HSBC, KBC, Natixis, Rabobank, Societe Generale, UniCredit, Banco Santander and Nordea, says it can proceed more nimbly than Marco Polo.

"We are ahead of the pack because we are not a consortium," Roberto Mancone, chief operating officer, We.Trade, told CoinDesk. "We are a legal entity and we are able to license solutions to banks and that's the main difference. We can license today and are not asking for banks to help us to build something."

Regarding the argument around future interoperability with the likes of insurance firms, he said that We.Trade is structured with an API architecture that can easily allow third-party providers on the platform.

In terms of connecting with other platforms, Mancone said that while it's not a priority at the moment he wondered what the future might hold in terms of connecting R3 Corda and Hyperledger, adding:

The standalone nature of trade finance deployments on Hyperledger, in the form of We.Trade and Batavia (which has the backing of IBM and Swiss bank UBS), may be what spawned a recent rumor that the two platforms might even merge.

But Mancone waved this claim away.

"We work on Hyperledger; they work on Hyperledger," he said. "Theoretically, it's good to know that there are some players out there using the same technology which increases the possibility of expanding platforms going forward."

And not all trade finance banks see things the way NatWest does. Nordea Bank, based in Sweden, offers an illustrative counterexample in its rationale for going with we.trade rather than Marco Polo.

Nordea was one of the first banks to join the R3 consortium and was also one of the early players around the table to talk about the Marco Polo project. However, in November of last year the bank decided to join the We.Trade platform, almost as an antidote to blockchain prototyping fatigue.

Ville Sointu, head of emerging technologies at Nordea, explained that after being brought in at the bank midway through last year he gathered the blockchain team under one roof and shut down almost all the prototyping. Nordea has narrowed its efforts down to We.Trade, plus a real estate pilot with the Finnish government, and a corporate identity blockchain.

Sointu said his team needed to understand the operational realities of making a blockchain network live in a banking environment.

"Those learnings are invaluable as we start to look at more complexity down the line and for other use cases as well," he said.

Sointu said he remains a big supporter of R3's Corda and wishes Marco Polo all the best in its plans.

"The reason we kind of scaled back the Marco Polo activity in favor of We.Trade was that We.Trade offered a clear business case and a clear path to production," said Sointu, concluding:

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