For a few days, it looked like the truce might hold, but on 24 June, a military helicopter was shot down in the east. Still, Ukraine's leaders persevered with the peace plan, but in early July it crumbled altogether with at least nine civilians killed. Both sides blamed each other - the fighting resumed with increased ferocity.
The Ukrainian military made the first serious gains, with the pro-Russian rebels losing much of the ground in the east and driven from their stronghold at Slovyansk. The insurgents have lost at least half of their territory since the beginning of July.
But many have retreated and regrouped at Luhansk and in Donetsk, the city of one million people close to the site of the crash. The rebels are reported to be changing their tactics, sending relatives away from the cities and digging in for a prolonged urban guerilla warfare.
"To respond to this phase... we evidently must change tactics," Valeriy Chaly, deputy head of the presidential administration, told the Associated Press news agency.
Pro-Russian fighters walk past the site of remnants of a downed Ukrainian army aircraft Il-76 at the airport near Luhansk, Ukraine. Photo / AP
Territory is frequently changing hands however as the balance of power shifts, and the rebels have maintained the ability to hit Ukrainian government forces with deadly attacks. Last week, 19 soldiers were killed in a hail of missiles. After renewed accusations that Russia was supplying sophisticated weapons including tanks and multiple rocket launchers, the Ukrainian military launched a round of air strikes on rebel positions near the border with Russia.
They have also targeted convoys coming from the border, desperate to disrupt the supply lines.
As the Ukrainian military increased its onslaught, patience in Moscow appeared to be wearing thin. When news of the first Russian casualty broke last week - a man was killed by a shell coming over the border - the Kremlin stepped up the rhetoric, with promises of "irreversible consequences".
Sanctions from the US and EU appear to have had little impact. The US has shown a willingness to provide the Ukrainian authorities with non-lethal military assistance, but if the next phase of the fighting does enter a guerilla war stage, the government is ill-equipped to counter it.
- Independent