The Pentagon maintains a strict policy of never sharing source codes for US weapons systems -- not even with its closest allies [15]. The F-35 software comprises over 25 million lines of code. Foreign nations receive no unsupervised access to the F-35 and its critical mission systems [15].
Only Israel holds a unique position: the F-35I "Adir" features Israeli-developed mission software and operates independently from the central US system [16][17]. The United Kingdom fought for five years to obtain an ITAR waiver for operational sovereignty [18].
Switzerland's F-35s are being procured through the FMS process [19]. This means:
Turkey was expelled from the F-35 programme in July 2019 after procuring the Russian S-400 system [20][21]. Ankara had already invested USD 1.4 billion in advance payments [20]. The case demonstrates that US export controls can be politically instrumentalised, and that even NATO partners are not protected from programme exclusion.
As a neutral state, Switzerland has neither NATO special status nor a strategic relationship with the USA comparable to Israel's. The F-35 procurement establishes a long-term political and technical dependency that extends beyond the aircraft's service life (30+ years).
Translated from the German version. See the German version for complete references.
→ See also: Procurement Costs and Cost Overruns