During the 1960s, at the height of the Cold War, the U.S. national military strategy called for the ability to fight "two-and-a-half wars." The thinking was that the nation might be challenged by the Soviet Union in Europe, China in Asia and a third contingency requiring U.S. military action elsewhere.
That three-front challenge is back.
China's aggressive moves over the South China Sea and the Sea of Japan involve threatening maneuvers by Chinese fighter jets against U.S. and Japanese patrol aircraft operating over international waters.
They stem from an expansive Chinese claim of sovereignty not sustained by international law. China is also exerting heavy pressure on Hong Kong's democracy rights. A new challenge over Taiwan by the increasingly strong Chinese military is probably not far off. The United States has promised to defend Japan and Taiwan.
In the Middle East, which the world depends upon for a large part of its oil supply, the picture is more complex. Armed religious and ethnic groups are competing in Iraq for territory and power.
The Syrian civil war pits Shia-led Iran and its ally, Syrian President Bashar al-Assad of the Shia-related Alawite sect, against various Sunni groups financed by oil money from the Persian Gulf, including the Islamic State, a radical jihadist group with global ambitions. Iran continues on a path to obtain nuclear weapons while helping to divide Iraq's Shias from a unified government.
The possible outcomes could present U.S. allies Saudi Arabia, Jordan, Turkey and Israel with serious threats.
Meanwhile, the war in Afghanistan continues.
In Europe, Russia has begun an aggressive campaign to regain territories lost on the breakup of the Soviet Union, with campaigns against Ukraine and Georgia and the potential of similar campaigns against NATO members Latvia, Lithuania and Estonia.
The rise in all three threats has coincided with, and may have been invited by, a retrenchment in U.S. military force projection and a White House policy of retreating from hot spots like Iraq and Afghanistan.
The reduction in U.S. military power is closely linked to the nation's budgetary crisis and the refusal of the White House to negotiate a long-term policy to bring entitlement spending under control.
It is hard to escape the view that the administration's policies have increased threats to the order on which world peace and prosperity depend.
In similar past crise the United States re-armed and strengthened foreign alliances. It needs to do so again. But it cannot succeed in restoring a more stable world order by waiting for other nations to take the lead, or by "leading from behind."
A recovery requires a change in priorities for this administration, or more likely, the next.
It also requires a new social compact that restores long-range balance to revenue and federal spending.
Only when it has its own house in order can the United States provide the world leadership that is so evidently lacking today.