"We always had concerns that, God forbid, this may turn into a sectarian clash. Now our fears are slowly becoming reality. This gives us cause to be concerned," Erdogan said this week.
Al-Maliki retorted Friday by effectively calling for Erdogan's removal from power, even as he warned that Turkey could be descending into civil war.
"Erdogan should focus his attention on addressing Turkey's domestic issues, which raise our concern, as Turkey heads toward civil war," al-Maliki said in a statement released by his office.
He predicted that the "Turkish people are looking forward to changing the political situation to protect Turkey from worsening domestic and foreign problems."
Turkey responded by deriding al-Maliki's comments as "nonsensical remarks," "groundless claims" and "fictitious evaluations." The Foreign Ministry said al-Maliki had "lost touch with reality" and "confused the state of affairs in Iraq with that of Turkey" and called on him to "abandon policies that escalate tensions in the country."
The United States in some ways is caught in the middle, committed to defending Turkey as a NATO ally but also linked with Iraq as a strategic partner that Washington is helping to arm.
Among the factors leading to the rhetorical volleys are two sets of clashes in the past week. According to news reports, 12 Iraqi troops died Monday in clashes with the Peshmerga, Kurdistan's self-defense force, near Tikrit. Al-Maliki sent tanks and armored vehicles to the oil-rich Kirkuk region - which both Kurdistan and the central government claim - among other incidents.
The other major clashes have occurred in Ras al-Ayn, just inside the Syrian border with Turkey, where forces of the rebel Free Syrian Army have engaged a Kurdish force affiliated with the Kurdistan Workers' Party for control of the border post. The Kurdish force, which Turkey, the United States and the European Union view as a terrorist organization, has been cooperating with the regime of Syrian leader Bashar Assad for some months.
The connection with the Syria conflict is that President Massoud Barzani of the Kurdistan Regional Government has sided with Turkey in opposing a takeover by Kurdish extremists of parts of northern Syria, whereas al-Maliki, presumably under Iranian pressure, has allowed Iranian aircraft to overfly Iraq with military equipment and support for Syria's government.
Now Barzani has informed Turkish leaders that he's very worried that al-Maliki, a Shiite Muslim with ever-closer ties to Shiite Iran, intends to use brute force against Iraqi Kurdistan.
In a showdown between Barzani and al-Maliki, Turkey almost certainly would back Barzani.
"So far, we have not been approached" for help, a Turkish official told McClatchy Newspapers on Friday. But he didn't reject support out of hand. "Let's see when and if they do" ask for help. "Let's see what they ask for."