The contrast could not be more stark. When we think of gang wars, we think of senseless killings, cruelty, innocent children getting killed, drugs, and turf battles. When we think of the wars our own troops fight, we think of sacrifice, freedom, honor, and loyalty. So to compare gang wars to the wars our country's troops fight seems to show the height of ingratitude, ignorance, contempt, idiocy, and lunacy. To compare gang wars and our nation's wars would indicate the worst of a person until we read Augustine and former Marine Corps Major General Smedley Butler.
Who was Augustine? Augustine lived in the fourth and fifth centuries and was a Bishop in the Christian Church. He was a prolific writer who was respected and followed by theologians from both the Roman Catholic and Reformed traditions.
What did Augustine say that would make our nation's war comparable with gang wars? Consider the following from the 4th chapter of the fourth book of Augustine's "City Of God." Augustine said that when a kingdom is without justice, it is merely a gang of robbers, or, in our language, a street gang. He continued in comparing the two by saying that both had authority figures, pacts and rules. The latter determined how their bounty was divided. When a gang grows large enough, it becomes a nation. 
This is what people of every nation must consider before embracing nationalism. Is one's nation merely a gang? The answer to that question lies in the presence or absence of justice. However determining whether a nation is just can be difficult because every country's résumé consists of claims of nobility, righteousness and justice. Even in the worst of nations, such as Nazi Germany, each nation sees itself as source of nobility and defender of freedom. Hence, we should go beyond the self-description of any country, especially one's own, and examine the actions of each nation using the same standards.
Now who was Smedley Butler? Smedley Butler was a Marine Corp Major General who lived from 1881 until 1940. He served in the Marine Corp for 34 years. He was awarded the Medal of Honor twice, which is a rare accomplishment.
What did Major General Butler say? He introduced us to a great divide between why the troops fight and why they are sent. He stated that for many years, he suspected that he was fighting for business interests, later he became sure of it. To make his point, Major General Butler pointed out some financial results of war. Results include the creation of 21,000 new millionaires and billionaires by the end of WWI. Results also include a ballooning national debt that consisted of $1,000,000,000 in 1898 when we had no outside territories $25,000,000,000 sometime after WWI and after acquiring outside territories that contained private investments as well as a future conflict with Japan over territories in the Pacific. What is interesting about Major General Butler's points is that he made many of the same points made by Helen Keller in a 1916 speech warning President Wilson not to enter WWI. In particular, Keller foresaw a war with Japan as a result of US acquisitions in the Pacific. We should note that the Japanese called WWII the Great East Asian War and that it was fought to liberate East Asia from Western colonialism.
We should then note Howard Zinn, a historian and WWII veteran, and his observations about why we fought WWII. He stated that despite all that was happening in Europe and the Pacific, we were doing business with and helped fascism emerge in Europe and we did not fight until one of our territories was attacked. 
And though we might think that we were fighting against racism in Europe by trying to save the Jews, Zinn shows how we were slow in responding to their plight. In addition, when our Black soldiers returned home, they faced the same hateful racism here as they faced before the war. 
And while we were told that we were that we were fighting for the freedom of the world and self-determination, our Secretary of State assured the French that we were sympathetic toward their desire to keep their territories, such as Vietnam. Other assurances were given and it wasn't long after the war, that we started to assist France in trying to maintain their hold on Vietnam. 
The point here is that there is a divide between the aspirations of the troops who fight and the reasons why our presidents send them into harm's way. Though our most of our troops see themselves as liberating the oppressed overseas and defending freedom at home, the reasons why they are sent to fight are often quite different. The reasons why our leaders send our troops off to war, according to Zinn, is for sake of profits for the wealthy and power for the government. That is not to deny that some good came from fighting; but it is to say that our ideals were not the main reason for sending our troops. 
We only need to examine our methods then to see how concerned we have been with justice. Here again, we find failure. For whether it was in Vietnam, in the Middle East, in Latin America, or even in Europe, we find that our methods either targeted civilians or made their deaths inevitable. In addition, we supported dictators and suppressed many democracies.
We now come back to Augustine. Without justice, our nation is nothing more than a gang and our wars become gang wars. It isn't a coincidence that often turf battles between gangs are fought for business reasons. One gang wants to expand its operations, such as drug dealing, and thus increase its profits. In addition, it is not odd to hear gang members talk like soldiers as they speak about honor, sacrifice, and fighting for one's brothers. Though we see on military ads the slogan of belonging to something greater than oneself, that same kind of belonging exists whenever we join a group. Often, the only difference between a gang leader and the leaders of a nation is that the injustice of a gang leader is plain for all to see; the injustice of our governmental leaders, both Republicans and Democrats, is subtle and is covered by an attractive veneer of idealism and good intentions. So even though our troops believe they are fighting an honorable fight, it is the motives of our leaders that determine whether the colors of our flag are being relegated to gang colors and their battles to gang warfare.
There is a solution to all of this. That solution is to broaden our vision. That solution includes a deemphasizing our nationalism so that our commonality as people trumps our differences by nationality. Of course, we know who propagates these anti-patriotic and hate America ideas. These notions are preached by the Jeremiah Wrights of America who can find nothing good to say about the country that has blessed them so. And though what I just wrote sounds like something Jeremiah Wright would say, he is not the one I am footnoting. Martin Luther King said:
"Our loyalties must transcend our race, our tribe, our class, and our nation; and this means we must develop a world perspective." 
It is when our loyalty to principle, love, and to all who have been made in God's image, as King reminded us in his writings, supersedes our sense of patriotism and being proud Americans that we can start to stop gang wars in the world.