Last year, Turkey bought the Russian S-400 anti-aircraft defence system, in spite of fierce objections from the United States.
In early October, S-400 units were being taken to the Black Sea, near Sinop in northern Turkey, for another round of tests that are likely to renew concerns among Turkey’s NATO allies and its neighbours.
What is the S-400 system?
Known as “Triumph” in Russia and “Growler” by NATO members, the S-400 surface-to-air defence system is one of the most advanced in the world.
Medium to long-range, its detection radar can spot and track incoming aircraft, directing a barrage of missiles at their targets to a range of 400km (249 miles).
By contrast, the US Patriot can only fire one missile at a time and go a quarter of the distance.
The S-400 can engage low-flying targets as well as those at high altitudes, and it can destroy incoming missiles that move at high speeds.
It is highly capable and is much sought after. Its missiles are highly manoeuvrable, reaching speeds of up to Mach 14, or 14 times the speed of sound, and can turn sharply, engaging and destroying targets no matter what the target tries to do. In short, it is deadly.
US, NATO concerns
A key NATO member and an important US ally, Turkey was considered an integral part of the F-35 stealth fighter programme and was earmarked to be one of the first countries to receive these advanced fighters.
It was also in the market for a decent air defence system. Washington’s reluctance to sell the US Patriot air defence system to Turkey, along with the Patriot’s patchy operational record, made Turkey turn elsewhere for alternatives.
Ankara signed the S-400 deal with Russia in 2017 with the first deliveries of four missile batteries worth $2.5bn arriving in July 2019.
Condemnation from the US of Turkey’s decision to buy the Russian air defence system has been loud and unwavering.
The US officially expelled Turkey from its F-35 fighter jet programme in July last year.
Washington is concerned that being part of a US stealth fighter programme is incompatible with owning and operating a potential adversary’s weapons system that is designed, in part, to shoot down US-made aircraft.
Would the S-400 be incorporated into NATO communications nets? Would it be able to extract valuable data on US stealth aircraft like the F-35?
With Russian trainers and personnel on the ground, acting as support for the S-400, this vital information could easily make it back to Russia.
Because of this, US President Donald Trump has threatened Turkey with sanctions if it goes ahead and uses the S-400.
Desperate to solve the crisis, US senators have put forward a buy-up option in which the S-400 is paid for by the US as compensation and locked up on Turkish soil, never to be used, with regular US verification visits.
This has been rejected by Ankara and tests have already commenced.
In the first operational test in November 2019, Turkish F-16 and F-4 jets were targeted by S-400 radars in a mock attack as they flew over the capital Ankara.
In August, a Hellenic Air Force F-16 was targeted with the S-400’s radar when returning from a multinational military exercise, with Turkey being sharply rebuked for its actions against a fellow NATO ally.
In early October, S-400 units were been taken to the Black Sea, near Sinop.
A radar test and possibly a live-fire of Turkey’s missiles has been scheduled, as a notice to airmen or NOTAM has been issued telling all aircraft to avoid that area to a height of 200,000 feet (61,000 metres).
United States condemnation at Turkey’s buying of the defence system has been unwavering [File: Vitaly Nevar/Reuters] Neighbours’ concerns
There are added concerns that the S-400 could be used offensively. Unlike the Patriot, the S-400 can engage many aircraft at once at a range of 400km.
This means that it could cover most of Syria. A battery placed at the border near Gaziantep, Turkey could engage aircraft as far away as Damascus and Beirut and could certainly reach any Russian aircraft taking off or landing at the Russian base in Khmeimim near Latakia, Syria.
A missile system that dominates an adversary’s air space is a potent weapon and can tip the strategic balance, making any military action on the ground more tempting.
However it is used, the S-400 has Turkey’s neighbours worried.
Greece, which operates an older version, the S-300, with little or no complaints from the US, is especially worried given it was a Greek fighter jet that the S-400 was tested on, as tensions simmer between the two NATO members.
The S-400 would allow Turkey to cover the whole of the Aegean and the eastern Mediterranean.
This was precisely the objection Turkey had when Cyprus bought the S-300 in the late 1990s – that Cyprus would be able to dominate the airspace between itself and a large chunk of southern Turkey.
Greece was obliged to take the system and have it moved to the island of Crete in order to avoid military action by Turkey against the Republic of Cyprus.
Wherever these batteries are placed, the S-400 will have a destabilising effect due to its potency.
It is yet unclear how Russia will react if it is deployed against Russian aircraft, a scenario all too possible in the near future as the two countries find themselves backing opposing sides in Syria and Libya.
Whether in northern Syria or in central Libya, this weapon will have the ability to shoot down its enemies with ease but will become a prime target for any adversary – at once a temptation and a danger to itself.