On Monday, four children of an American and his Israeli wife killed by the Palestinian terrorist group Hamas in 2015 filed suit against Turkey’s Kuveyt Turk Bank in a New York court. They charge that the bank helps Hamas finance its terrorist attacks, allegations the firm is almost certain to deny.

The lawsuit against this Shariah-compliant bank, which counts the Turkish government as a shareholder, comes two weeks after the US Treasury sanctioned 11 Turkey-linked entities and individuals for supporting Hamas and other jihadist outfits. The evidence keeps mounting: Turkey has become a haven for regional baddies.

Under President Recep Tayyip Erdogan, Turkey has become a permissive jurisdiction for rogue regimes and their illicit bankers. Between 2012 and 2015, Tehran relied on Turkish banks and a dual Iranian-Turkish gold trader to circumvent US sanctions at the height of Washington’s efforts to thwart the Islamic Republic’s nuclear ambitions. It was the biggest sanctions-evasions scheme in recent history.

Similarly, Venezula’s Maduro regime has been using Turkish-based companies in a money-laundering network involving the sale of Venezuelan gold. The US government sanctioned that network in July.

Reports suggest that a Treasury-sanctioned money man for the ­Assad regime in Syria owns an extensive network of companies in Turkey, thus enabling Syria to circumvent US sanctions.

Turkey has also proved a forgiving host to terrorists. In April, Treasury sanctioned six individuals and a Turkish money exchange for their role in bankrolling Islamic State. The action underscored how Islamic State terrorists continued to operate from Turkish territory well into 2018.

Turkish law enforcement is known to turn a blind eye to jihadists, while the country’s courts treat them leniently, often releasing them pending trial or granting them parole — in stark contrast to harsh treatment meted out to secular and pro-democracy dissidents.

After their ouster from Egypt in 2013, the Egyptian Muslim Brotherhood established new institutions in Turkey. In addition to Islamist propaganda, the movement’s television stations have broadcast death threats against Egyptian officials and foreign nationals in Egypt. Ironically, the Turkish government defends the Muslim Brotherhood’s “freedom of expression” even as Erdogan has silenced Turkey’s domestic opposition.

Turkey stalks and prosecutes dissident groups with zeal, branding them terrorists, while allowing actual terrorists from Hamas to operate freely on Turkish soil. Saleh Arouri, the Hamas military commander responsible for the 2014 kidnapping and killing of three teens in the West Bank, spearheaded that operation from Turkish soil. The US Treasury designated Arouri as a terrorist in September 2015 and subsequently issued a “Rewards for Justice” bounty for information leading to his arrest or capture.

But Arouri is just one of many Hamas operatives who have operated in Turkey. In 2011, 10 Hamas operatives Israel released as part of a prisoner exchange arrived in Turkey, and many remain active there. Imad al-Alami, Hamas’ long-serving envoy to Iran and a US-designated terrorist since 2003, received medical treatment in Turkey in 2014 and continued his work there while he convalesced.

The New York lawsuit against the Kuveyt Turk Bank has the potential to check Turkey’s impunity. In 2016, the nonprofit St. Francis of Assisi filed a complaint in California against Kuveyt Turk Bank and its parent company, Kuwait Finance House, for allegedly processing donations to Islamic State. A federal judge dismissed the case because it couldn’t be proved that a US person had been harmed.

By contrast, Monday’s complaint against Kuveyt Turk has plaintiffs with ties to the United States. The plaintiffs also argue that the bank is subject to jurisdiction in New York for using its correspondent bank accounts in the Empire State to facilitate US-dollar-denominated transfers for Hamas’ benefit.

It’s already clear that Erdogan’s Turkey has become a permissive jurisdiction for illicit and terror finance. But this new case on behalf of an American victim of terrorism and members of his family could finally begin to hold the regime in Turkey responsible.

Jonathan Schanzer, a former terrorist finance analyst at the US Treasury, is senior vice president for research at Foundation for Defense of Democracies, where Aykan ­Erdemir, a former Turkish parliamentarian, is a senior fellow.