August's incidents follow July's firing of three ballistic missiles into the sea, a mid-range missile launch in June, a long-range rocket launch in February and the country's fourth nuclear test in January.
Since the isolation nation first started testing missiles in 1993, it's been a thorn in the sides of South Korea, Japan, the U.S. and, increasingly China. The development and proliferation of Pyongyang's missile industry is viewed as major security threat, not only because of the frequent threats leader Kim Jong Un issues to Washington and Seoul, but because missile technology is linked to the country's nuclear capabilities.
North Korea is believed to possess more than 1,000 missiles of various models, including intercontinental ballistic missiles (ICBMs) that are used to fire nuclear warheads, according to the National Committee on North Korea, a non-partisan research coalition.
Existing UN Security Council resolutions prohibit the country from using ballistic missile technology, "even if characterized as a satellite or space launch," and enhanced sanctions were adopted in March in response to January and February's incidents. The country has been under sanctions since 2006.
Only the U.S., China and Russia can stop North Korea's recent escalation, according to Michael Ivanovitch, president of research firm MSI Global and a former OECD senior economist. "But that hinges on whether the three superpowers can agree among themselves about the balance, and the political nature, of power on the Peninsula."
For now, that doesn't seem likely.
"Their interests don't coincide. They were on the opposing side of the Korean War and the sequels of that conflagration are still unresolved," Ivanovitch explained. Moscow and Beijing were essential sources of tactical, military and logistical aid for Pyongyang during the 1950-1953 conflict with South Korea, while Washington was an ally to Seoul.
The heated debate about deployment of a U.S. anti-missile defense system, known the Terminal High Altitude Area Defense (THAAD), in South Korea is a current example of those underlying tensions. Seoul and Washington hope to use THAAD to counter North Korea, but Beijing and Moscow are against the idea, calling THAAD a regional security threat.