Mexico and Pakistan are at risk of a "rapid and sudden collapse," according to a recent report from the U.S. Joint Forces Command.
The assessment comes as President-elect Barack Obama prepares to tackle international challenges including the conflict in Gaza, the wars in Iraq and Afghanistan and tensions between India and Pakistan.
"In terms of worst-case scenarios for the Joint Force and indeed the world, two large and important states bear consideration for a rapid and sudden collapse: Pakistan and Mexico," the report says.
A spokeswoman for the U.S. Joint Forces Command said the latest assessment was likely written before the Mumbai attacks which further inflamed tensions in South Asia.
The Joint Operating Environment report, meant to examine worldwide security trends, says Pakistan, in the event of such a rapid collapse, would be susceptible to a "violent and bloody civil and sectarian war" made more dangerous by concerns over the country's nuclear arsenal.
The report says that "perfect storm of uncertainty" by itself might require U.S. engagement.
The report says a collapse in Mexico seems less likely, but noted that the government infrastructure is "under sustained assault and pressure" from drug cartels and gangs. A collapse within the United States' southern neighbor would also "demand an American response based on the serious implications for homeland security alone."
Obama met earlier this week with Mexican President Felipe Calderon.
Joint Forces spokeswoman Kathleen Jabs told FOXNews.com the purpose of the assessment is not necessarily to predict future crises with 100 percent certainty, but to start a dialogue among world leaders by "looking at the trends."