U.S. President Donald Trump’s decisiveness has borne fruit against North Korea following threats by its dictator, Kim Jong Un, to launch a missile strike against the continental U.S. Although the North Koreans blinked first and quickly got down from their high horse—successfully taming the “rocket man,” as Trump named him, from Pyongyang by striking an agreement with him—removing the threat he poses to the safety and peace of the Far East is still far away.

It’s a shame that Washington did not adopt the same decisive stand against North Korea to either Syria or Iran, far weaker rivals than North Korea. Unfortunately, the Americans were unsuccessful in convincing Syrian President Bashar Assad and the rulers of Iran to take them seriously. Instead, Damascus and Tehran are listening to Trump’s promise that the United States will leave Syria. They find it difficult to believe that there is any real substance behind American officials’ seemingly empty declarations that Assad’s blood-soaked regime has lost its legitimacy, or that Washington is determined to stop Iran from becoming a regional power and threatening U.S. allies in the Middle East.

As opposed to the North Korean crisis—where the American administration has clear-cut goals, not to mention policy and a plan or action—the only apparent goal in the Syrian crisis is withdrawing from the country as quickly as possible. The Americans came to Syria in the beginning to fight Islamic State but since the success of their operations against it, they apparently do not see any reason to stay in Syria or continue being involved.

The Russians and Iranians are filling the void left by the Americans, both economically and militarily. In the meantime, they are successfully transforming Assad’s slaughterhouse into a sanctuary safe from any attack. Now the Russians are threatening to sell Assad the S-300 surface-to-air missile-defense system, among the most advanced in the world. Assad does not need such weapons to keep on massacring his people. Such systems will also not stop a potential American missile barrage; the only one under threat by these missiles is Israel. In the past, Israel declared that it would not let Syria arm itself with these weapons, but that was before the Russians arrived.

The Russians are not an enemy, however, not of Israel and not of the United States. Despite the rivalry between Washington and Moscow, understandings can be reached that will respect the interests and the balance of power between the two superpowers. Washington needs a clear-cut policy and a plan of action for such understandings to be reached. It must decide what to do with the Kurds it aided in the fight against Islamic State. In addition to the Kurds, Washington has to decide what to do with the groups of rebels in areas like southern Syria that vested their hopes in America, now that they are being annihilated by Assad thanks to Russian and Iranian support. Finally, it must decide how to curb the continuous Iranian presence on Syrian soil.

This May, Trump is expected to reopen the Joint Comprehensive Plan of Action, the nuclear deal that the Barack Obama administration negotiated with Tehran. It is important not to repeat Obama’s mistake of limiting discussions with Iran to the nuclear question. Instead, Trump must discuss subversive Iranian activity throughout the Middle East, which stretches through Syria, Lebanon, the Gaza Strip, Iraq and Yemen. In general, Trump must remember that tolerating Iran in Lebanon, Yemen, Iraq and Syria make it more difficult to contain the Iranian threat.

Iran, for its part, chose to open a new hostile front with Israel. Last weekend, Tehran threatened once again to throw Israel into the sea. However, these threats remain empty, not only because of the fatal blow Iran will be forced to take if it attempts to attack Israel. Tehran is boasting to raise low morale and turn the attention away from severe economic problems at home and, primarily, to deter the United States and Israel from any attempts to foil the Iranian presence in Syria.

The Iranian challenge demands a root canal, not a topical cream like Obama’s JCPOA. The case of North Korea proves it is appropriate to threaten and, faced with no other option, bring results through military action. On the other hand, blinking first makes the Americans seem weak.

Eyal Zisser is a lecturer in the Middle East History Department at Tel Aviv University.