On July 31, the deadline the United States set for Turkey to abandon its deal with Russia for the S-400 missile system expired. As Ankara continues its efforts to negotiate with Washington and convince it not to impose sanctions, pundits in the West have started to talk about a major shift in Turkish foreign policy. Some have gone as far as to suggest that Turkey has "turned its back on the US" and is gravitating closer to Russia.
While this is not the first time a NATO member has bought a military system from Moscow - Greece purchased the S-300, the older version of the S-400, in 1996 - the Turkish-Russian deal comes at a time of heightened tensions between the West and Russia and increasing fractures within the transatlantic alliance. It has caused a "first of a kind" internal crisis in the alliance and has gotten Washington worried.
The purchase of the S-400 will indeed affect Turkey's strategic alliance with the US, but it will not break it. In the future, Ankara will have to balance between its 67-year-old NATO membership and other partners, rather than replacing one with the other.
A multipolar world
To understand why Turkey decided to purchase a Russian weapons system, it is important to put the deal within the context of global developments over the past few years.
When NATO was formed 70 years ago, world affairs were dominated by a cold conflict between two superpowers - the Soviet Union and the US. After the collapse of the USSR, Washington moved to impose a unipolar order in the world, which lasted close to two decades. Today, however, various powers, including Russia and China, are becoming increasingly assertive on the international stage as the world gradually shifts to a multi-polar system.
As a result, traditional alliances are shifting and countries are adjusting their foreign policies to accommodate this new reality. The US itself has revised its approach to dealing with old friends and foes.
For example, disagreements between Washington and its European allies have been mounting, especially over the latter's level of defence spending and proposals to establish an EU army, supported by the leaders of France and Germany. US President Donald Trump has also scorned Western European allies over their energy imports from Russia. Last year he lambasted Germany for its dependence on Russian gas and its decision to proceed with the Nord Stream 2 gas pipeline project.
In short, there is a serious divide within Europe and NATO over various issues, including relations with Russia. That, however, has not stopped the Trump administration from seeking to engage with Moscow.
Trump has not only held a number of one-on-one meetings with his Russian counterpart, Vladimir Putin, but his administration has also sought to closely work with the Kremlin on a number of issues, especially the Syrian war.
In February, Israeli Prime Minister Benjamin Netanyahu, Trump's closest ally, paid a visit to Moscow and presented Putin with a joint plan for US-Russia-Israel cooperation on Syria. This was followed by a trilateral conference on June 25 between Israeli, Russian and US national security advisers, the first event of its kind.
If the US is seeking engagement beyond its traditional alliances, why shouldn't other actors do so as well?
Turkey's considerations
It is not just the changing nature of alliances that is causing Ankara to try to balance its foreign relations. Turkish officials have complained that over the past few years, the US has not been a reliable partner. Its alliance in northern Syria with the People's Protection Units (YPG) - affiliated with the Kurdistan Workers' Party (PKK) - and its failure to cooperate on extradition requests for Fethullah Gulen - who the Turkish authorities accuse of masterminding the July 2016 coup attempt - have driven a wedge between the two old allies.
Above all else, the US did not greenlight Ankara's insistent request for Patriot air defence systems until Turkey secured the S-400 agreement with Russia. Even after that, it provided Turkey with tougher terms on pricing and joint production - compared to the ones offered by Moscow - which amplified the mutual lack of trust even further. This pushed Ankara to accept Moscow's proposal to supply the technology it needed to protect itself from threats in Syria, Iraq, and Iran.
Washington was quick to caution Turkey against pursuing such a deal. It has worried that the Russian missile system could collect intelligence from NATO's infrastructure and that Russian military experts would be involved in its operation. Both the White House and the Pentagon have warned that this procurement would have a detrimental impact on Turkish interoperability with NATO and might overshadow military-to-military cooperation between the Turkish army and its Western allies.
In response, Turkish officials have repeatedly assured the US that NATO and Russian equipment will be kept separate to avoid Russian access to US stealth technology and that the Turkish military will have full control over the S-400. They have also argued that Turkey's exclusion from the US F-35 fighter jet programme after the conclusion of the S-400 will weaken the security of NATO's southern wing.