Given that the Book of Mormon is a compilation of the parts of Nephite history that would be important for us to know about, it is fair to assume that this focus on war indicates that war would play a big part in the history of the world in the latter days, and clearly it does. It also provides us with an example of how a righteous army and army leaders would conduct themselves during war times.
One theme that is repeated often in Alma is that the Nephites are justified in going to war for the sake of defending their liberty, including their religious liberty.
47 And again, the Lord has said that: Ye shall defend your families even unto bloodshed. Therefore for this cause were the Nephites contending with the Lamanites, to defend themselves, and their families, and their lands, their country, and their rights, and their religion.
14 Now the Nephites were taught to defend themselves against their enemies, even to the shedding of blood if it were necessary; yea, and they were also taught never to give an offense, yea, and never to raise the sword except it were against an enemy, except it were to preserve their lives.
As American troops moved into Iraq to remove Saddam Hussein from power, President Hinckley recounted much of this in his 'War and Peace' General Conference talk and also said:12 We would subject ourselves to the yoke of bondage if it were requisite with the justice of God, or if he should command us so to do.13 But behold he doth not command us that we shall subject ourselves to our enemies, but that we should put our trust in him, and he will deliver us.14 Therefore, my beloved brother, Moroni, let us resist evil, and whatsoever evil we cannot resist with our words, yea, such as rebellions and dissensions, let us resist them with our swords, that we may retain our freedom, that we may rejoice in the great privilege of our church, and in the cause of our Redeemer and our God.
"It is clear from these and other writings that there are times and circumstances when nations are justified, in fact have an obligation, to fight for family, for liberty, and against tyranny, threat, and oppression."Whatever flaws there may have been with the execution of the war in Iraq, the end result is that the people Iraqi people have more liberty than before and are are free from the brutal dictatorship of Hussein and his sons.
In Syria things are not quite the same. Syria is no paradise of liberty and has one of the worst records for upholding human rights in all the world. While that makes it easy to quickly sympathize with people who are trying to overthrow the government there, not all change is for the better.
The rebels are not striving to bring democracy and freedom and safety to their country, they seek power to impose their own dictatorship, one that could also likely turn oil-rich Syria into a source of massive international terrorism. Videos can easily be found on Youtube showing the rebels (deeply connected with terrorist groups like Al-Qaeda) acting in a manner that fits in well with the war atrocities recorded in Moroni 9. Their barbaric actions make the speculation that they used chemical weapons on their own people to draw the USA into the fight to help them win credible. This is not a battle between good and evil, this is a case of the wicked destroying the wicked.
That is something we've seen in the Book of Mormon before as well, both at the end of the Nephite and the Jaredite civilizations. In those cases, the prophet of the day chose to stay out of it, and it would seem to make sense for the USA to follow that path here as well.
There is no freedom to defend or establish here and you can't join the fight without joining up with the bad guys. There is nothing for the US to gain from supporting the rebels, and there will be no benefit to the Syrian people either should they win in the end. Humanitarian aid for non-combatants is fine, but taking sides isn't going to serve a purpose. Egypt has already been destabilized thanks in part to US meddling. I would hope they would learn from that and think twice before making the same mistakes in Syria, but I'm not going to count on it.