To those Muslims looking to expand Islam's global reach, symbolism is very important.

In the weeks after 9/11, photographs circulated within the Muslim world of the New York skyline, its normally dominant World Trade Center replaced with photo-shopped mosques, identifiable by their prominent domes and minarets.

The depiction represented an Islamic conquest on U.S. soil, providing it with a strategic foothold. Becoming an Islamic shrine demanded further action be taken to follow up on this victory to turn symbolism into reality.

Throughout history, Islam has built mosques in lands it conquered. That is why the effort was launched, several years after 9/11 to build the "Ground Zero Mosque" two blocks from where the WTC collapsed.

The 9/11 attack brought to light certain sensitivities within both the Muslim and non-Muslim communities in addition to another symbol important to the former.

After 9/11, U.S. President George W. Bush called for a "crusade" against a new kind of evil -- i.e., terrorism. Using "crusade" in the context of a "noble goal," he subsequently stopped the reference due to the negative connotation it had among Muslims.

While "crusade" generates the same negativity among Muslims as the word "jihad" does among non-Muslims, the latter have refrained from calling for a "crusade" although Muslims continue their call for "jihad."

Muslim sponsors claimed building the Ground Zero Mosque would help bring back the atmosphere of "interfaith tolerance and respect that we have longed for since Muslims, Christians and Jews lived together in harmony and prosperity 800 years ago."

To understand this statement is to understand Islam's hypocrisy.

First, Islamic scholars agree, "Wherever Muslims live and have mosques, it is impermissible for any sign of infidelity to be present, churches or otherwise."

But the right of "taqiyya" allows Muslims to deceive non-Muslims as to their actual intent to advance Islam. Mosque supporters claiming the scholars' statement is untrue are simply exercising taqiyya.

Second, wanting to imprint the mosque with a name bearing significance for Muslims but lost on naive Americans, sponsors settled upon "Cordoba House" -- after a city symbolizing one of Islam's greatest victories.

"Cordoba" was a Spanish city conquered by the Muslims centuries ago, whose citizens were forced to submit to Islam. In keeping with the practice of conquering Islamic armies to memorialize a battle's victory by constructing a mosque where it was won, one was built. A site where a Christian church once stood gave way to a mosque.

The "harmony" referenced above, therefore, was "Muslim harmony" as non-Muslims were ruled by Muslims.

Since 9/11 is viewed by some Muslims as a conquest of the United StatesS, they believed the New York site, like Cordoba, similarly had to be memorialized. Thus, using "Cordoba" symbolized a "middle-finger salute" to America.

Mosque supporters set their sights upon the old Burlington Coat factory building, valued at $18 million before 9/11 but damaged during the attack, buying it for less than $5 million. Yet to be disclosed is the mosque's $100 million funding source for renovations.

Additionally, the relatively small size of Lower Manhattan's Muslim community should bring into question the need for such a large -- 13-story -- mosque.

In 2010, U.S. sentiments against the Ground Zero Mosque's construction ran high. Over time, supporters took a lower profile, accurately assessing such sentiments would fade. Quietly, they continued to put their construction plans into action to make Cordoba House a reality, changing the name to "Park51."

Peeling back the complex layers of Islamic groups and individuals behind the mosque reveals linkage to the Muslim Brotherhood -- an organization whose goal, as documented in its leadership's own writings, is to bring Shariah law to the United States, ultimately displacing the U.S. Constitution.

Despite Islam's influence on the 9/11 attack, the United States has continued to keep the doors of tolerance open to a religion clearly motivating some followers to pursue violence against it.

In the years since 9/11, there has been a significant increase in the number of mosques built in New York. Where these mosques have been built, steps have been taken later by Muslims to close businesses providing un-Islamic services, such as selling alcohol.

Like areas in Paris, which are "no-go" zones for non-Muslims, some areas in New York have become similar zones for non-Muslim vendors. The effort is slowly turning non-Muslim neighborhoods into Muslim footholds to convert locals to Islam.

And Islamists have found converts to be good fodder for terrorist activity.

Interestingly, since 9/11, as mosque construction has blossomed in the West, so, too, has the intimidation and persecution of non-Muslims in Muslim countries, forcing them either to close their houses of worship or leave.

Supposedly "moderate" Muslim countries like Saudi Arabia prohibit other religions from being practiced. Thus, the West's tolerance has been met with continuing intolerance by Muslim states.

A surprising discovery was made April 25 by surveyors inspecting the Ground Zero Mosque site on behalf of its owner. In a small trash-filled alley passageway, found wedged between the mosque and an apartment building next door, was the 5-foot high landing gear of one of the Boeing 767 aircraft flown into the WTC by Islamic hijackers.

This discovery, almost 12 years later, opened old wounds for those who lost loved ones on 9/11, especially the 1,000 families of victims whose remains were never found.

As mentioned, symbolism is important to Muslims. Perhaps non-Muslims should see some symbolism in the discovery, years later, of a 9/11 plane's landing gear. For one, it should symbolize that the victims of 9/11 never be forgotten.

But just as important, it should symbolize in "plane" language a warning about Islam: Muslims aggressively increase their global footprint methodically and deliberately while decreasing that of non-Muslims passively accepting their doing so.

(Lt. Col. James G. Zumwalt, a retired Marine infantry officer, 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.)

(United Press International's "Outside View" commentaries are written by outside contributors who specialize in a variety of important issues. The views expressed do not necessarily reflect those of United Press International. In the interests of creating an open forum, original submissions are invited.)