Norway is saying that it will not commit to buying F-35s unless it gets a formal commitment to integrate Kongsberg joint strike missile (JSM):

Norway’s Kongsberg has warned that the country needs a commitment from the US government within six months to integrate a national-specific missile on the Lockheed Martin F-35, or it could withdraw from the programme.

So far, Norway has received no assurance that the Kongsberg joint strike missile (JSM) will be integrated as part of the Block 4 software update on the F-35 in 2019.

The absence of such a commitment could prompt the Norwegian parliament to reject an expected request early next year from the nation’s defence ministry to buy the first four F-35s, in order to launch training activities in 2016.

“That is what I think is the critical issue [for the parliament’s decision]”, said Bjorne Bjune, Kongsberg vice president of business development, speaking at the Air Force Association’s annual convention in Washington DC on 20 September. “That decision needs to be forthcoming.”

Integrating the JSM as the Norwegian F-35’s primary surface-to-air missile system killer is considered an absolute requirement by Oslo, Bjune said. Norway has already invested $1 billion to adapt the naval strike missile into the air-launched JSM, and is planning to spend a further $200 million.

One of the unspoken goals of the JSF program, from the American perspective, is to kneecap the development of systems related to the JSF, either by not allowing integration of foreign systems into the aircraft’s (very) closed architecture, or by making it prohibitively expensive.

The problems that are occurring now, when Lockheed and the Pentagon are trying to convince allies to purchase the aircraft, are nothing compared to what we will see once the planes start to enter other inventories.

Simply put, once your country commits to purchasing the JSF, you will find nothing but delays, stonewalling, and excessive costs if you want to integrate, or update, an indigenous system into your fleet.