Global leaders from politics, defence and diplomacy meet in Germany from Friday to discuss conflict hotspots and looming threats, from Syria and Afghanistan to East Asia and Africa.
Some 20 heads of state and government, 50 foreign and defence ministers, 10 chiefs of world bodies as well as top military brass will gather for the Munich Security Conference (MSC).
A tight police cordon will secure the three-day event, where UN chief Ban Ki-moon, the US secretaries of state and defence and the Russian and Iranian foreign ministers are on the high-powered guest list.
The annual meetings, launched 50 years ago at the height of the Cold War, have typically focused on US and European -- notably NATO's -- efforts to tackle the world's trouble spots.
This year's meeting comes as transatlantic ties, already seen as waning as the United States looks more to the Asia-Pacific, have been dealt another blow by revelations of sweeping surveillance by Washington of its allies.
The scandal, including the alleged tapping of German Chancellor Angela Merkel's mobile phone, will overshadow talks that are meant to focus on common challenges, from conflicts in the Middle East and Iran's nuclear programme to the unrest in Ukraine and tensions between China and Japan.
"Many will have Mr (Edward) Snowden at the back of their minds," said the MSC organiser, German veteran diplomat Wolfgang Ischinger, referring to the fugitive US intelligence contractor.
US Secretary of State John Kerry and Defence Secretary Chuck Hagel will likely send the message that "Washington has understood that substantial repair work is needed" to heal the alliance, Ischinger said.
At a pre-MSC panel talk last week, the US ambassador to Berlin, John Emerson, gave a foretaste of their joint pitch when he said "fully rebuilding trust will take time and will require sincere efforts on both sides of the Atlantic".
"Good friends disagree, but they also work out their differences. We will get through this because we must."
The 50th MSC comes in a year of other key anniversaries -- 100 years since the start of World War I, 75 years since World War II broke out, and a quarter century since the fall of the Berlin Wall.
It also falls as NATO-led forces are set to end major combat operations in Afghanistan this year, with a future multinational military training and support mission still uncertain.
Wrapping up the costly Afghanistan engagement will, however, not leave NATO without a purpose, said its deputy chief Alexander Vershbow at the panel talk.
"Terrorism, cyber attacks, proliferation, instability beyond our borders -- those are reasons enough to keep NATO alive and kicking," he said.
"We need an alliance that is ready to deal with anything that the future might throw at us."
But he reiterated a common US criticism -- that "European allies must do more for their own and our shared defence" -- pointing to low military spending and the use of incompatible weapons systems.
He said many leaders on the continent had not yet understood "the critical need for Europe to be able to back up its soft power with hard power if it wants to play a meaningful international role".
Conference host Germany, often criticised for its post-WWII reluctance to send troops abroad, is expected to signal somewhat greater support for its key EU ally France in Africa missions such as Mali and the Central African Republic.
For some commentators, the annual talk-fest of the Western security community comes at a time when the old order has already all but broken down, as highlighted by its inability to broker an end to the protracted war in Syria.
The West is "in a period of strategic drift, with an increasingly isolationist superpower that seems to have lost the spirit to lead and a self-centred Europe unready to step up to the plate," wrote Clemens Wergin, foreign editor of Germany's Die Welt daily, in The New York Times.
"We can see in Syria what such a world might look like, with rogue states, regional wannabes and non-state actors filling the vacuum that America's absence has created."