Gaza was demolished in three weeks. Rebuilding it will take years

The rebuilding of Gaza after the Israeli bombardment already faces unique problems and is likely to be the most difficult reconstruction project in the world. This is because of the sheer scale of the devastation, the economic siege of the Palestinian enclave by Israel and Egypt, and the attempt to exclude Hamas, the elected rulers of Gaza, from any role in the rebuilding.

The difficulties are all the greater because of the destruction of much of the tunnel system linking Gaza to Egypt. Israeli and European leaders talk of the tunnel system – by one estimate there are 1,100 of them – as if it was exclusively devoted to supplying weapons and ammunition to Hamas. In reality, "the tunnel economy" has been the way in which food, fuel and everything else has reached Gaza since Israel and Egypt sealed off the Strip 18 months ago, when Hamas drove out the rival Palestinian faction Fatah in 2007. Military supplies were always a very small part of Gaza's imports through the tunnels.

"Everything from Viagra to diesel entered Gaza through the tunnels," said one source. At one point before the Israeli attack, the price of petrol went down in Gaza because a pipeline had been threaded through one of the tunnels, all of which are privately dug and owned. Cooking-gas bottles are in short supply because they previously came in through tunnels that are now closed.

"I know middle-class families in Gaza cutting up their furniture to build fires so they can cook their food," said an aid official yesterday. Spare parts are desperately needed for generators.

The Palestinian tunnels and the Israeli-Egyptian border closure were two issues at the centre of the war and their future is still unresolved.

Until Gaza has continual access to the outside world, any real reconstruction will be impossible. A senior EU official said no aid would be spent rebuilding buildings and infrastructure while Hamas remained in control.

Israel says that it will have withdrawn all its troops from the Gaza Strip by the time Barack Obama is inaugurated today. A first priority forthe UN Relief and Works Agency (UNRWA) will be to bring in foodstuffs and medicines and rebuild its supply system stretching from the Israeli port of Ashdod to the Gaza Strip. Then it will try to restore the electricity, water and sewage systems wrecked by Israeli bombs and shells. Amnesty International yesterday accused Israel of war crimes, saying its use of white phosphorus munitions in densely populated areas of Gaza was indiscriminate and illegal.

UNRWA will probably carry out the preliminary assessment of damage and initial repairs because Israel, Egypt, the US and the Europeans are boycotting Hamas, although UNRWA is nervous of acting as a substitute government of Gaza. One Palestinian estimate suggests that the cost of rebuilding will be $1.4bn (£970m). Saudi Arabia has already pledged $1bn but promises on aid are seldom kept in full.

Rebuilding will take place in a 139-square-mile enclave that is packed with 1.5 million Palestinians, of whom 70 per cent are from refugee families expelled from Israel during the creation of the state. More than a million are already receiving UN food supplies.

The initial assessment is that 20,000 homes lived in by 120,000 people have been somewhat damaged and can be patched up so they are habitable again. The 4,000 homes that have been destroyed cannot be rebuilt because Israel is refusing to let construction materials cross the border into Gaza.

Israel, the US and their European allies are eager to prevent Hamas taking charge of reconstruction because this might add to its political standing among Palestinians. They recall that after the Israeli attack on Lebanon in 2006, many Lebanese at first blamed Hizbollah for provoking the assault. But Hizbollah took charge of rebuilding and Iran reportedly gave $14,000 to every family which had lost its home, money that was channelled to grateful recipients through Hizbollah.

The major potential donors for Gaza will try to get aid distributed through the Palestinian Authority of President Mahmoud Abbas. But he is, if anything, more discredited in the eyes of Palestinians and the Arab world as an Israeli and American stooge than he was before war in Gaza. Hamas, which won the heavily-monitored Palestinian election of 2006, will not want to dilute its power but there will be international pressure on Palestinians to form a government that is acceptable to donors.

If Gaza is to be restored even to the miserable condition it was in before 27 December, then the economic siege has to be lifted. But Israeli leaders like the Foreign Minister, Tzipi Livni, and the Defence Minister, Ehud Barak have claimed success in the war. If the blockade is raised, then Hamas will say it won the war – and the election of Benjamin Netanyahu as the next Prime Minister of Israel in the election on 10 February will become even more certain.

So were there any winners or losers?

What was Hamas's aim? Rocket attacks intended to force Israel to end blockade that has trapped 1.5m Palestinians inside Gaza Strip since Hamas takeover. Hamas also seeking recognition by West

What happened? Security arrangements are to be imposed on Hamas and no ceasefire agreement has been signed with the Islamists

Did they succeed? No.

What was Israel's aim? Gaza offensive launched to "teach Hamas a lesson". Some Israeli politicians called for overthrow of Hamas, while contenders in next month's election sought improved ratings

What happened? The majority of the estimated 20,000 Hamas fighters escaped with their lives. Hamas rockets were still being fired at the end of Israeli offensive when Israel declared unilateral ceasefire

Did they succeed? No.

What was Egypt's aim? To secure end to offensive through ceasefire agreement leading to truce, border security, reopening of crossings, Israeli troop withdrawal and Palestinian reconciliation

What happened? US negotiated separate deal with Israel on arms smuggling. Hamas set its own truce conditions and refused reconciliation with Fatah. Egyptian mediation deepened split between moderate Arab states and others

Did they succeed? No.

What was the EU's aim? To profit from power vacuum in US and play lead negotiating role. To map out road to peace and promise support for Palestinian leadership afterwards

What happened? Plethora of negotiators undermined EU credibility as didthe incompetence of Czech EU presidency

Did they succeed? No.