In August 1998, a splinter group of the Irish Republican Army set off a car bomb in the Omagh section of County Tyrone in Northern Ireland that killed 29 people and two unborn babies and injured 220 others.

The bombing prompted Bono, the lead singer of the Irish rock band U2, to write a song titled "Peace on Earth" that lists the names of some of the people killed in the bombing along with powerful lyrics:

"I'm sick of hearing again and again that there's gonna be peace on Earth."

The song hits home as another holiday season arrives in the midst of so much turmoil at home and abroad. While there is much to be thankful for there is also great unease.

Last week, an off-duty Turkish police officer assassinated Russia's ambassador in an art gallery in Ankara, setting off global alarm and raising questions about larger consequences from an emboldened Vladimir Putin.

The gunman shouted "God is great" in Arabic and said in Turkish: "Don't forget Aleppo. Don't forget Syria," before he was killed by security forces.

The gunman was calling attention to the bloodbath taking place in the Syrian city where a brutal civil war has raged for almost six years, leaving some 400,000 people dead. Even the wincing photos and desperate cries of the children in Aleppo have failed to focus the world's attention on a viable solution to the humanitarian crisis.

"Heaven on Earth, we need it now."

On the same day as the assassination in Turkey, a truck plowed through a Christmas market in Berlin, killing 12 people and wounding dozens more. The Islamic State claimed responsibility for the attack, adding to the mounting political pressure on Chancellor Angela Merkel of Germany, who rightly had opened the country's border to about one million asylum seekers from conflict zones in the Middle East and North Africa.

Border closings, mass deportations, turning a blind eye, and xenophobia are not solutions to civil wars, terrorism or attacks on innocent people.

"They say that what you mock, will surely overtake you.

And you become a monster, so the monster will not break you."

According to the Institute for Economics and Peace, a think tank that produces a Global Peace Index, just 10 countries can be considered completely free from conflict.

But Harvard psychologist Steven Pinker argues in his 2011 book, The Better Angels of Our Nature, that the world has become more peaceful.

Between 1945 and 1990 there were 30 wars that killed more than 100,000 people each. But in recent years war zones have contracted while other forms of violence have declined, including murder, capital punishment, torture, and domestic violence.

In the United States, the violent crime rate has fallen by more than half since 1990. But daily shootings continue to plague big cities like Philadelphia.

"Hear it every Christmas time, but hope and history won't rhyme

So what's it worth?

This peace on earth."