ANKARA — When a long-simmering conflict in the south Caucasus burst into open warfare this week, Turkey’s President Recep Tayyip Erdogan was the first world leader to jump into the fray.
His mission was not to calm tensions between the warring parties, Azerbaijan and Armenia. Instead, he declared all-out support for the Azerbaijanis, close Turkic allies, and accused Armenia of ignoring efforts to negotiate a resolution. He also demanded that Armenia withdraw from lands it occupied 30 years ago.
“I condemn Armenia once again for attacking Azerbaijani lands,” he said. “Turkey continues to stand with the friendly and brotherly Azerbaijan with all its facilities and heart.”
Dozens have been killed in four days of fighting since Azerbaijan and Armenia began missile strikes against each other’s positions along a front line that has been frozen since a territorial war between the former Soviet republics in the 1990s. On Thursday, the American, Russian and French presidents together called on both sides to cease hostilities.
Turkey supplies weapons and training to Azerbaijan, and there are signs that it is actively engaged in the fighting, which Ankara has denied. If Turkish involvement is confirmed, even in a supporting role, it would be just one of several fronts where Mr. Erdogan has deployed troops, ships and aircraft with increasing readiness this year.
Turkey is engaged in the wars in Syria and Libya, it has mounted repeated military operations against Kurdish forces in Iraq, and it is pressing territorial claims in disputes with Greece and Cyprus. This more aggressive foreign policy has alarmed Turkey’s NATO allies but has won Mr. Erdogan a certain respect at home, at a time when the country is suffering economically and his party’s popularity is flagging.
And as in Syria and Libya, Mr. Erdogan finds himself on the opposite side of the Caucasus conflict from Russia in an increasingly complicated geopolitical rivalry. Analysts see both the conflicts in Libya and the Caucasus as extensions of the struggle between Turkey and Russia in Syria.
Mr. Erdogan’s growing assertiveness has come partly in response to changing global dynamics, particularly the shrinking American role in the region, deep divisions within the European Union and the devastating civil war in Syria, just across Turkey’s southern border. He has at his disposal a powerful military that Turkey has been upgrading for decades.
The increasing militarism abroad mirrors Mr. Erdogan’s combative personality, his taste for gunboat diplomacy and the belief that flexing his military gives him a place at the table with the big powers.
“Turkey’s approach to the Caucasus is deceptively simple, and in line with its logic in other theaters of conflict/dispute,” tweeted Selim Koru, an analyst at TEPAV, a nonprofit think tank in Ankara. “Turkey-Azerbaijan are stronger than they were in the 1990s vis-à-vis Armenia. They feel that the territorial distribution needs to reflect that reality.”
Both Turkey and Azerbaijan are richer and militarily better equipped than they were in 1994, when Azerbaijan ceded control of the disputed enclave of Nagorno-Karabakh to Armenia after years of fighting. At that time, Russia warned Turkey not to come to Azerbaijan’s aid.
“There is a broad consensus that the region is in flux in terms of regional power,” said Ryan Gingeras, professor at the Naval Postgraduate School in California. “So Turkey has had the opportunity to play a much more expansive role.”
Turkey has been careful to avoid direct conflict with Russia when they are on opposing sides, and to fight opponents who are weaker militarily — Kurdish guerrilla fighters in Iraq, Libyan militias and the Syrian army. Its successes have only emboldened it, Mr. Gingeras said.
“They have not only achieved their goals but done so in rather, from the inside out, spectacular fashion,” he said. “And that has really been a gratifying realization, so that Turkey will continue to grow hungry as it eats, knowing that it will continue and will be able to perhaps affect other regional parties by using or threatening to use military force,” he said.
“It is definitely a harbinger of what is to come,” he added.
At the beginning of the year, virtually single-handedly, Turkey took a stand in northwestern Syria, managing to stall a blistering air and ground offensive by Russian and Syrian forces and to hold on to a portion of the last opposition-held Syrian province, Idlib.
In May, Turkey deployed military advisers, weaponized drones and Syrian proxy fighters to Libya to shore up the U.N.-backed government in Tripoli and push back Russian contractors who were supporting an assault on the capital.
Turkey’s success in reversing the momentum of the war stunned many, although Russia forced it to halt its push toward Libya’s lucrative oil fields.
With its presence in Libya established — and plans afoot to build bases and train the Libyan army — the Turkish navy projected an increasingly assertive presence in the eastern Mediterranean.
Turkish naval vessels accompanying a supply ship to Libya prevented a French attempt to search the vessel, which led to a NATO investigation. An entire fleet escorted Turkish drill ships exploring for gas in waters off Cyprus, defying the European Union.
When Armenia killed a general and other officers of Azerbaijan’s army in a missile strike in July on the decades-old cease-fire line between the two countries, Turkey immediately offered help in preparing a response, according to a retired Turkish general, Ismail Hakki Pekin.
“Azerbaijan for a very long time used to have an issue of lack of self-confidence,” he told the Turkish daily Yeni Safak. “The response to those attacks is very important in that sense. The drones, armed and unarmed, that have been provided by Turkey, have been very effective in those operations.”
After the attack in July, Azerbaijan and Turkey undertook joint exercises and made defense plans, he said.
Mr. Erdogan’s opponents at home criticize his methods but generally support his stance. Many Turks saw the intervention in Libya and the demand for greater maritime rights in the eastern Mediterranean as in Turkey’s interests, and the country overwhelmingly sides with Azerbaijan in its conflict with Armenia.
And the belligerence does not all come from Mr. Erdogan. The military, though diminished politically, remains a powerful institution in Turkey, with capabilities honed as part of NATO. There has been a move since the 1990s, before Mr. Erdogan’s tenure, to build a domestic defense industry, which now produces armed drones — made by a company owned by Mr. Erdogan’s son-in-law, Selcuk Bayraktar — warships and attack helicopters.
Turkey has built up its navy, long a lesser part in the armed forces, to the point that it will far outstrip Greece as a naval power in coming years. Within the next five or 10 years, Turkey will have one or two light aircraft carriers and a number of frigates, including guided missile ships, that would be entirely produced at home, Mr. Gingeras said.
“This would make it a navy that, in local terms, was really the power of the eastern Mediterranean, at least among local states.”
Armenia claims a Turkish F-16 shot down an Armenian fighter jet, though officials from Azerbaijan and Turkey have denied that.
And President Emmanuel Macron of France said on Wednesday that there was evidence that a proxy force of Syrian fighters had been deployed from southern Turkey to Azerbaijan. A Syrian fighter confirmed the presence of those forces, which Azerbaijan and Turkey have denied.
Despite Turkey’s refusal to confirm the use of Turkish armed drones in the Caucasus, Mr. Bayraktar posted Azerbaijan’s defense ministry footage of drone strikes on Twitter on the first day of the conflict.
There is concern among many Turks that Mr. Erdogan, who has alienated European and Western allies with his growing authoritarianism, has no exit plan for his interventions.
Ahmet Davutoglu, who served as prime minister under Mr. Erdogan, warned Tuesday that Mr. Erdogan’s talent for making enemies and dispensing with formal diplomatic channels was dangerous, especially when it concerns Armenia and Azerbaijan.
“Taking military steps will cause greater problems in the Caucasus,” he said. “It is clear there is no proper coordination with Russia,” he added.
But Mr. Erdogan is as much a chess player as Russian President Vladimir V. Putin, intent on preventing on outright Russian victory and further humanitarian disaster in Syria, said Asli Aydintasbas, a Turkish analyst with the European Council on Foreign Relations.
“They always push each other to the brink,” Ms. Aydintasbas said.
Andrew Kramer contributed reporting from Moscow and Aurelien Breeden from Paris.