In today’s world of a Donald Trump presidency in which any actions he undertakes, regardless of its logical rational, becomes a topic of criticism by his political opponents, we must look at two of his decisions – independent of the tainted lenses through which critics choose to view them – made concerning Syria.

The first, following chemical weapons usage by President Bashar Assad’s regime against his own people, involved Tomahawk missile strikes against the airfield from which the aircraft laden with those weapons of mass destruction (WMD) operated.

Pundits like to claim that presidential candidate Trump declared in 2013 that we should not intervene in Syria and, therefore, his missile attack is hypocritical. Such pundits take an unrealistic view of a world arena in which a nation’s actions one day may not warrant a U.S. offensive response but, the next day, very well may. Assad’s chemical attack clearly fell into this category for several reasons: it was a war crime; it involved complicity by the Russians and President Barack Obama, who both knew such weapons remained in Syria’s inventory despite their assertions otherwise; and it demonstrated, by the attack’s brutality against his own people, of what Assad is capable.

Fortunately for his Middle East neighbors, Assad today is denied a nuclear option with which to threaten them. Pundits undoubtedly have forgotten that Iran and its nuclear and missile research R&D puppet, North Korea, were collaborating on building a nuclear facility in Syria until 2007, when Israeli aircraft put an end to that effort by destroying it. A dictator fully capable of employing WMDs against his own people would not hesitate to use them against others.

The second decision we need examine is Trump’s announcement U.S. ground troops would not be sent into Syria. This, too, is logical, based not only on the realities of what such forces would face on the ground today in Syria, but also the realities of a war we earlier lost in Vietnam.

As one looks at the players involved in Syria today, it becomes apparent all is not black and white. While our main interests in Syria lie in stabilization and protecting its civilian population, the vast majority of whom are Sunni Muslim, we are hampered by Assad, of the minority Alawite Muslim sect, and his cronies in Tehran, who are Shiite Muslims. It was the large Sunni Syrian population that initially rose up against Assad due to his brutal reign, causing the dictator to put down those protests. While the U.S. initially saw its interests achieved only with the removal of Assad from power, American officials later said they would accept his leadership if elected.

This chemical attack against his people has more recently underscored the need to dethrone him. Today, we support “moderate” Muslim Sunni groups against Assad, which we may well find tomorrow are not so friendly.

It must be kept in mind our interests are directly opposed by Iran’s which, contrarily, lie in keeping Assad in power so as to continue with the expansion of the regional Shiite caliphate on which its mullahs remain focused. This caliphate, to date, has targeted once-Christian majority Lebanon, where Iran’s terrorist proxy, Hezbollah, is active; Shiite-majority Iraq, which only fought an eight-year war (1980-1988) with Tehran because its leader, Saddam Hussein, was Sunni; Libya, where various factions vie for full power; Yemen, where a once obscure rebel group known as Houthis, who are Shiites, rebelled against the government.

Obviously included in Iran’s caliphate equation is Syria. (Iran will eventually look to bring another Shiite majority state, Azerbaijan, into the caliphate fold but, right now, has its hands full in these other countries). Also noteworthy is that Iran and Russia are working together to undermine U.S. interests in Sunni-majority Afghanistan.

During the Vietnam war, while the U.S. poured ground forces into the country to stem the flow of Hanoi’s efforts to take control of the country, we were confronted with powers in that region having contrary interests that proved able to draw the conflict out, engaging us in what was then our longest war. Countries like China and Russia achieved this by providing Hanoi with an unlimited supply of equipment, vehicles, surface-to-air missile launchers, arms, ammunition, etc. Similarly, Iran today provides its proxy forces with these assets which, were there to be U.S. ground forces committed to Syria, would drastically increase.

The leader of the North Vietnamese Army, General Nguyen Giap, prided himself in conducting a war against America not involving major confrontations of massive armies but, rather, numerous limited smaller unit engagements the Chinese call “lingchi” or “death of a thousand cuts” to bleed America dry and into withdrawing. This would also be Iran’s modus operandi against U.S. ground forces. Interestingly, it has been aided in supplying its proxies today with war material by Obama’s administration which, as part of its nuclear deal with the mullahs, gave them billions of dollars in cash to continue their violent regional activities.

There is another factor distinguishing the Vietnam war from the turmoil in Syria if U.S. ground forces were to be involved. While China and Russia’s interests opposed America’s in Vietnam, U.S. ground forces never confronted the ground forces of any other nation state as Hanoi was fully committed to providing its own manpower to do so. In Syria, Iran already has its own ground forces actively involved, such as the Islamic Revolutionary Guard Corps, thus making a direct confrontation with our main adversary much more likely.

During the early 1960s, several military advisors informed Presidents John F. Kennedy and Lyndon Johnson Vietnam was not the right place at the right time to confront communist aggression. However, if the U.S. were to get involved in Vietnam, it should go in “air heavy” and “ground light.” This advice is just as sound today for a 21st-century battlefield situated thousands of miles away from Vietnam where foreign-supported aggression has again reared its ugly head. With his announcement not to commit U.S. ground forces to Syria, President Trump has made the right decision at the right time.

Lt. Colonel James G. Zumwalt, USMC (Ret.), is a retired Marine infantry officer who served in the Vietnam war, the U.S. invasion of Panama and the first Gulf war. He is the author of “Bare Feet, Iron Will–Stories from the Other Side of Vietnam’s Battlefields,” “Living the Juche Lie: North Korea’s Kim Dynasty” and “Doomsday: Iran–The Clock is Ticking.” He frequently writes on foreign policy and defense issues.