Turkey’s decision to suspend trade relations with Israel shows how conflict in the Middle East is reverberating across the wider region, but it also speaks to slow but seismic shifts in the domestic Turkish political landscape. So Ankara’s balking at Jerusalem, and the decision made this week on trade, could ultimately be more intriguing than commercially consequential. 

“Export and import transactions related to Israel have been stopped, covering all products,” according to a statement released Thursday. The statement added that Turkey “will strictly and decisively implement these new measures until the Israeli Government allows an uninterrupted and sufficient flow of humanitarian aid to Gaza.”

Last year the two countries had trade estimated at $6.8 billion. Turkey is also a popular vacation destination for Israeli travelers, and it was not immediately clear to what extent tourism would be affected by the developments.  This, though, is just the latest round in a trade war that Turkey started in April when it imposed a number of restrictions on exports to Israel.

These include construction materials. Later that month President Erdogan, who is an outspoken critic of Israel and Prime Minister Netanyahu, welcomed a delegation of Hamas terrorist ringleaders to Istanbul. Could these developments be related? Both the escalating trade wars and outreach to Hamas come only about a month after Mr. Erdogan’s drubbing at the polls.

The loss was for his ruling Justice and Development Party, known as AK, which suffered a serious setback in local elections across the country, a member of NATO. Once the dust from those election results settled, the mayor of Istanbul, Ekrem Imamoglu, emerged stronger than ever. Mr. Imamoglu, 52, is a Kemalist and widely seen as a top presidential contender.

Mr. Erdogan, a year into his second five-year term, has already indicated he won’t run again. Meantime, the situation in Gaza is already galvanizing. Mr. Imamoglu has told CNN that Hamas’s attack on Israel is something that “we deeply regret,” but said that “any organized structure that carries out terrorist acts and kills people en masse is considered a terrorist organization by us.”

Those words signaled that the battle for the presidency has begun — especially considering that the AKP spokesman, Omer Celik, openly criticized Mr. Imamoglu, calling his comments “completely wrong.” This, as well as Turkey’s decision to join South Africa’s case against Israel at the International Court of Justice, reflect Mr. Erdogan playing to his AKP party’s Islamist base.

Just how far will Mr. Erdogan go? As if welcoming Hamas honchos Ismail Haniyeh and Khaled Mashal to Turkey last month weren’t troubling enough, there are signs that the pair are in no great hurry to return to their regional perch at Doha. Mark, too, the recent comment of a former Israeli intelligence official and regional analyst, Avi Melamed.

“While both Qatar and Hamas have denied that international pressure on the emirate has forced serious dialogue surrounding the continued presence of Hamas’s politburo in the country, it seems that the delegation of Hamas political leaders, chaired by Ismail Haniyeh himself, that arrived in Turkey on April 19 might have come for more than just a ‘temporary visit,’” Mr. Melamed says.

If that is the case, it would not exactly be a big surprise. On Thursday, the same day that the halting of trade with Israel was announced, Mr. Erdogan doubled down on his criticism of the Jewish state. The 70-year-old leader reiterated his commitment to keep the spotlight on Israel’s “genocide” against the people of Gaza despite pressure from what he called the “global Zionist lobby.” 
He didn’t stop there, calling “the recent increase in defamation campaigns targeting Turkey” and himself  “not a coincidence,” but attempts to “silence Turkey.” He also said that “Turkey rejects antisemitism in the same way it opposes Islamophobia, xenophobia, and all forms of cultural racism.” Ankara is also however now rejecting Israeli goods, and Mr. Erdogan is calling the shots at least for the moment.