The most important strategic development in the Middle East these days isn’t the Trump administration’s decision, which was foreseen, not to move the U.S. Embassy from Tel Aviv to Jerusalem. Intelligence services in Israel and the region are now following events along the Syria-Iraq border.

In both countries, Shi’ite militias, backed by Iran, are moving toward the border. If they can come together on both sides of the frontier and create a band of control, a longtime Iranian aspiration will be fulfilled: to establish a land corridor through which the Iranians can freely move forces, weapons and supplies from Tehran through Iraq to the Assad regime in Syria, and even west of there to Hezbollah in Lebanon.

The creation of this contiguity would follow an achievement chalked up by the Iran-led axis in the region thanks to Russian intervention for the Assad regime in the Syrian civil war. Since the final surrender of the rebel forces in Aleppo in northern Syria last December, the regime and its supporters have slowly expanded their hold on various parts of Syria.

At the same time, the Iranians, through local Shi’ite militias, are helping the United States and Iraqi government fight the Islamic State around the Iraqi city of Mosul. Moving ISIS away from the border lets the Tehran-backed militias take strategic territory in the desert area west of Mosul near the Syrian border.

About a week ago, Shi’tite militias took over a number of villages around the town of Baaj on the Iraqi side of the border, pushing out Islamic fighters. The militias are accompanied by Iranian advisers and instructors. Reuters reported that the conquest of the villages will let the Iranians and their supporters reopen a good portion of the main road connecting Baghdad to the areas under Assad’s control in Syria. For complete territorial contiguity, Assad’s forces must still advance on the Syrian side in the area where the Kurdish militias are operating, supported by the United States.

“The Syria-Iraq border is at the moment the most important place in the region. That’s where the regional picture will be determined,” Chagai Tzuriel, director general of the Intelligence Affairs Ministry, told Haaretz over the weekend. Tzuriel, a former head of research in the Mossad, added that the creation of territorial contiguity under Iranian influence changes the strategic balance in the Middle East. According to Tzuriel, “Iran, with the assistance of the Shi’ite militias and the cooperation of other forces, continues to take steps whose goal is strengthening its hold in Syria.”

Tzuriel said that alongside their operations on the Iraqi-Syrian border, the Iranians have been in contact with the Assad regime to lease a port in northwestern Syria. This would give Iran a foothold on the Mediterranean coast – something Prime Minister Benjamin Netanyahu warned about on his visit to Moscow in March.

The stabilizing of the Assad regime thanks to Russian military support, along with the daily circus around U.S. President Donald Trump, have reduced media coverage of events in Syria. But Syria is the main arena of conflict, where the struggles between the superpowers are being waged and temporary or long-term alliances are being formed.

In Trump’s visit to Riyadh last month, where he signed a huge deal to sell American weapons to the Saudis, he expressed support for the Gulf states and warned against Iran’s intentions. But actually it seems Iran is advancing step by step toward its strategic goals.

For now, it’s not clear whether the new administration in Washington plans to take steps beyond rhetoric to halt Iran’s influence. Most of the U.S. military’s moves in the region are directed against the Islamic State, and in Trump’s speeches, he often focuses on the Iranian dangers, especially in the context of the recent terror attacks by Islamic extremists in Britain – in Manchester and before that in London.

On May 18, in an unusual move, the U.S. Air Force attacked militias identified with the Assad regime when they approached a base near Tanf on the Syria-Jordan border. U.S. special forces are operating in the area, alongside Syrian rebel forces that maintain a relationship with the Americans. The bombing seems to have been an isolated event that does not reflect a greater degree of commitment by Washington or a willingness to operate methodically in this region.

Israel’s statements on Syria mainly involve events closer to home – a lack of stability near the Jordanian-Syrian-Israeli border and what seems to be the Syrian regime’s attempts to gradually restore control along its border with Israel in the Golan Heights. Israel has already stated its opposition to the arrival of the Iranian Revolutionary Guard and Hezbollah fighters to the Golan if Syria is successful in its efforts.

Most of the Israeli attention is on an area that now has its own Hebrew acronym that translates as R.S.S. (region of southern Syria). But it seems that east of there, on the Syria-Iraq border, in an area that could also affect Jordan, a new reality is coming into being with implications that could affect the region in the coming years. At the moment at least, it’s the Iranians who are dictating this reality, while the other parties are watching from afar and still trying to draw conclusions.