COLOGNE, Germany — French and German officials celebrated the signing of a new defense export agreement last month as a watershed moment, but political and industrial mistrust remains a wild card for the Future Combat Air System program — an envisioned sixth-generation fighter jet.

The export pact, which entered into force in late October with the formal exchange of government notes, is meant to streamline a contentious process that has clouded bilateral defense cooperation for some time. Namely, the agreement dictates that joint government programs, like FCAS fighter jet, be free from interference by partner nations when it comes to eventual exports.

The clause is mainly aimed at Germany, where politicians and lawmakers tend to scrutinize weapons deliveries to countries with known or suspected human rights abuses more heavily than their French colleagues.

The situation has grown more tense since the October 2018 death of journalist Jamal Khashoggi, who Western officials believe was murdered by order of Saudi Arabia. Germany has since frozen all exports to the kingdom, prompting an outcry from France, where companies had to stall deliveries of equipment to Saudi Arabia in all cases where even a small number of components originated from Germany.

The new agreement ensures “nobody can throw a wrench” into the other’s export planning, says Matthias Wachter, chief defense analyst at the Federation of German Industries lobbying group. Having such a guarantee in writing is good news for FCAS and its ground-focused sister project, the Franco-German future main battle tank known as the Main Ground Combat System, he added.

The language of the export pact is reminiscent of the 1971 Schmidt-Debré agreement, named for the German and French defense ministers at the time and panned in the left-leaning Spiegel magazine as an “embarrassing pact” when reporters found out about the then-secret understanding a year later.

Fast-forward almost 50 years, and defense cooperation remains a thorny subject between the two countries destined to spearhead Europe’s envisioned military autonomy in the coming decades. And there are also long-standing cultural differences that linger. There is a perception among some German lawmakers, for example, that cooperation with Paris inevitably means ceding power to French influence to the point that Germany plays only second fiddle, according to Wachter.

That sentiment has led appropriators to craft a package deal for FCAS that would release funding for the next phase — building subcomponent demonstrators — only when there are assurances that Germany’s tank makers, namely Rheinmetall, play a prominent role in the Main Ground Combat System effort. With armored vehicles traditionally being a strong suit for German industry, some here have privately complained about the 50-50 division of responsibility.

“It’s an emotional issue here in Germany,” Wachter said.

Once the money begins to flow for an additional set of contracts early next year, there is a litany of questions yet to be sorted out. The fate of intellectual property rights, for example, remains unsorted, according to the analyst. In addition, as of late October, there was no agreement on Spain’s industrial work share. Spain is something of a junior partner in the FCAS project, though officials in Madrid have said they expect equal treatment as a full member of the trinational project team.

The Spanish government in the summer designated defense electronics company Indra as the national lead for the fighter program. The move angered Airbus, where officials were hoping to give their Spanish subsidiary a role that would satisfy Madrid’s demands for industrial participation.

Another potential point of contention has to do with military requirements for the future fighter. Perhaps the most prominent issue is that French officials want a carrier-capable jet, which Germany does not need.