globalization will only serve as a barrier to warfare for so long Finfan, it would be a very dangerous mistake to think that has changed in the era of global markets and online social networks.
While there were no online social networks pre-WW1, the level of global trade relative to global GDP took a nose dive with WW1 and has only recently really recovered.
Furthermore, trade is much more intertwined now than in 1913. During the Belle Epoque the "metropolis" were much more integrated with their own empires than with other nations. The supply chain was therefore still very much within the control of their own state. The nations which were most intertwined were Great Britain, France and the USA, which all ended up on the same side anyways. In the present there is no major nation that can sustain itself outside of trade relations as they stand today. Take Venezuela, for example, who's government is quite clearly "opposed" to the current international order. Venezuela's economy still depends almost entirely on their oil exports to the USA, the nation that Chavez likes to criticize the most. This is why only total "pariah" states, or states with little to no economic value to the global supply chain, can be attacked/invaded. Such was the case with the mess in the Balkans in the 1990s, and then with Afghanistan, Iraq and Georgia. If a state that is valuable to the global economic structure is attacked, then the global reply will be quick and effective, for example with Kuwait in '91.