Complex sentence: The Romanian government was forced to retreat to Iasi, Moldavia, but was able to stave off complete collapse thanks to the numerous Russian reinforcements that had been sent to Moldavia to prevent a Central Power invasion of southern Russia.
Split into simpler sentences: The Romanian government was forced to retreat to Iasi, Moldavia. However, the government was able to stave off complete collapse, thanks to the numerous Russian reinforcements that had been sent to Moldavia to prevent a Central Power invasion of southern Russia.