The BBC's security correspondent Frank Gardner looks back at the major security flashpoints in the passing year.
Once again the ongoing conflicts in Iraq and Afghanistan have dominated the global security landscape in 2006 and they look set to continue to do so in the year to come.
Daily death toll from violence in Iraq is now nearly 100 people a day
Almost the only thing that President Bush's administration and al-Qaeda have in common is that they both see Iraq as the central front in their conflict.
Iraq under President Saddam Hussein, of course, had a negligible connection with al-Qaeda, but followers of that organisation have taken full advantage of the chaotic security situation left by the 2003 US-led invasion, and more specifically by the disastrous decision to disband the Iraqi army.
Al-Qaeda does not always operate in concert with other insurgent groups, and in 2006 there have been signs of internal tension within the insurgency. But collectively the insurgents have made large parts of the country ungovernable by the central government.
The conflict has also shifted from being primarily one of Arab insurgents attacking US and Iraqi government forces to a low-intensity civil war based on sectarian divisions, with Sunni and Shia militias carrying out a seemingly endless series of tit-for-tat killings and reprisals.
Almost nowhere outside the heavily fortified Green Zone in Baghdad is safe, either for Iraqis or for foreigners.
IRAQ TIMELINE - 2006
Jan - the Shia-led United Iraqi Alliance wins polls, but fails to gain an absolute majority
Feb onwards - a bomb attack at Samarra's Shia shrine unleashes a wave of sectarian violence
May - a new government is formed, ending months of political deadlock
June - Al-Qaeda leader in Iraq Abu Musab al-Zarqawi is killed
Nov - Saddam Hussein is sentenced to death for crimes against humanity
Dec - the Iraq Study Group report released, describing the situation as grave
Random kidnappings have become commonplace, sometimes for ransom, sometimes for political ends.
More often than not, those kidnapped end up being handcuffed, tortured with power drills, murdered and dumped on rubbish tips. Suicide bombings are now a daily occurrence in Baghdad, especially in Shia areas, and the national death toll from violence is averaging close to 100 people a day.
When I used to visit Iraq in the Saddam era I found most ordinary Iraqis living in fear and hatred of his tyrannical regime.
When I went back in 2003 following the US-led invasion I found widespread relief in the south that he had been overthrown.
Yet today, those Iraqis who can afford to have been leaving the country in their thousands, seeing a new life in neighbouring Jordan, Syria or the Gulf as their best or perhaps only hope of survival.
Even many Shia, who were especially persecuted by the Saddam regime, have been saying that life was safer under him than now.
Not all of Iraq is as violent as Baghdad and Anbar Province, the worst affected areas, and much of the Kurdish north is peaceful and prosperous.
But the cohesion the country enjoyed under Saddam, albeit at a terrible price in human rights and lives, has been lost.
The US administration, which has been slow to admit how badly the occupation has gone wrong, remains publicly committed to building up Iraq's newly reformed police and armed forces to a level where they can safeguard security, allowing coalition forces to withdraw to bases and eventually go home.
But there are profound problems with both factionalism and professionalism.
The police have been heavily infiltrated by militias - kidnapping of Sunnis by men dressed in police uniforms is a frequent occurrence - and only a small number of Iraqi units are capable of taking on the heavily armed and well-motivated militias without US support and leadership.
Ultimately, Iraq's future in the short term will depend largely on what course President Bush decides to adopt in the wake of recommendations made to him by various policy groups.
These include the Baker-Hamilton Iraq Study Group, whose suggestions include involving Iran and Syria in pacifying Iraq. This move which would involve a 180% U-turn for Washington, which considers both countries to be sponsors of state terrorism.
Meanwhile, as the violence continues in Iraq, it continues to feed the global jihadi network with recruits, propaganda, combat-hardened veterans and extremist ideology.
As long as Iraq remains violent, al-Qaeda is always likely to have a base in the Middle East.
After four years of being dubbed "Op Forgotten" by British troops serving in northern Afghanistan, the rumbling conflict there mushroomed in 2006 into something far more serious.
Taleban fighters have stepped up their attacks in 2006
As of 18 December, a total of 190 coalition soldiers were killed in Afghanistan in 2006 - more than the total for both the previous years combined.
Casualties among Afghans - Taleban, government forces and civilians - have rocketed up into the thousands.
The Taleban appears to have imported and adapted insurgent tactics from Iraq, making both the roadside bomb and suicide bombing commonplace. Both were unheard of in Afghanistan until recently.
From their rear bases just across the Pakistani border, Taleban commanders made it clear in early 2006 that they would make every effort to resist the deployment of Nato forces to the south of the country.
Yet the ferocity of the Taleban campaign - which they see as one of national, patriotic and holy resistance to outside invaders - seems to have taken Nato commanders and Whitehall by surprise.
When I put this to Britain's Defence Secretary Des Browne at a conference, he replied that the Taleban "had not behaved according to type" - that is they had stayed and fought rather than hit and run.
Certainly the Taleban's tactics have been suicidal at times and they have taken enormous casualties.
But it would be a grave mistake for Western governments and military commanders to see body counts as a measure of military success in this conflict (which is what the US military did in Vietnam).
Every dead Taleban fighter has a brother, cousin, father or uncle who will be tempted to avenge his death, either by directly volunteering to fight or by giving money or other support to the movement.
Fight for hearts and minds
Even Afghanistan's beleaguered President Hamid Karzai, whose authority is weak at best in the south and east of the country, has publicly voiced his dismay at the high numbers of Afghan Taleban getting killed in this conflict.
In 2007, the barometer of success for Nato in pacifying this under-developed country is likely to be in whether it can win over support from the Afghan population.
So far, the fighting - and ensuing cost in property and civilian lives - has overshadowed international attempts to "rebuild" the infrastructure (which in many places was minimal).
The bottom line for Afghans is whether they see their future with the elected Nato-backed government of Hamid Karzai or with the draconian, but highly motivated, and well-recruited Taleban.
2006 saw the resurgence of conflict in Lebanon after nearly 16 years of peace.
The villages and towns in Lebanon still bear the scars of the conflict
The month-long summer war between Israel and Hezbollah ended inconclusively for both sides.
Neither Israel's air force nor its ground offensive succeeded in dealing a knockout blow to the Iranian-backed militia, nor did Israel secure the return of its captured soldiers.
But Hezbollah took heavy casualties and Israel believes it has now made it clear that any similar provocations along its border by Hezbollah will bring heavy and painful reprisals to Lebanon.
Partly due to the massive damage inflicted by the IAF (Israeli Air Force) on Lebanon's civilian infrastructure the war effectively boosted Hezbollah's popularity, winning it support even from non-Shia Christians and Sunnis.
There is a weary feeling of pessimism in the region that the Israel-Hezbollah conflict is unfinished business and could well resume in the near future.
Iran's nuclear programme is causing huge headaches in Washington, Europe, the Arab Gulf states and most of all, in Israel.
President Ahmadinejad is holding firm in the nuclear stand-off
The official Iranian line is that the programme is for purely peaceful, civilian purposes, for example to generate energy.
However military analysts point out that Iran's well-developed arsenal of long-range missiles is pointless unless they are tipped with either chemical or nuclear warheads and Iran has historically concealed its uranium enrichment activities from UN inspectors.
Throughout 2006 the hardline Iranian Government of President Mahmoud Ahmadinejad has rebuffed Western offers of technological help in exchange for suspending its enrichment programme (an essential first step in building a nuclear bomb).
Best estimates are that Iran is still several years away from possessing such a doomsday weapon but that it is almost bound to be aiming for the option to build one.
Israel - which the Iranian president has frequently said has no right to exist - is naturally nervous.
But unlike Iraq, whose nuclear facilities Israeli warplanes destroyed in 1981, Iran's facilities are buried deep underground.
There is therefore a reluctant admission in Washington that there are no easy military options for preventing Iran from acquiring the bomb.