"All military analysts must admit that that battle was organised as armies established long before would have organised battles," Mesic said in Okucani, 150 southeast of Zagreb, adding that Flash had been led in accordance with all military rules.
Asked by the press to comment on announcements by some retired generals and volunteers' associations that they would boycott the marking of Flash's tenth anniversary and that only the elite would come to Okucani today, Mesic said "the representatives of the authorities are elected by Croatian citizens".
"If they fought for this state and Croatia, then they also fought for Croatian institutions, so I don't understand why they are doing this," Mesic added.
Prime Minister Ivo Sanader said he could not comment on said announcements.
"When such operations' anniversaries are being marked everyone should come together, regardless of different political positions and beliefs," he said, adding that the state committee which organised the event had invited to Okucani all commanders who with their units had taken part in Operation Flash.
"The Croatian people and the Croatian state will never forget the operation which liberated Western Slavonia nor the later operations which liberated central Croatia," the PM said, adding that those operations were part of Croatia's foundations.
He went on to say that in 1991 the prevalent opinion in the international community was that Croatia could not oppose the Serbian aggression.
"Many thought Croatia would not manage to create an armed force which would liberate the territory. It turned out, however, that Croatia had the strength to do it."
Sanader said Croatia had succeeded in "creating a strong armed force which managed to liberate the entire country and forever remained a guarantor of Croatian security and integrity of state territory".
In memory of 42 soldiers and police killed in the operation, wreaths were laid at the Central Cross in Okucani by Sanader, Mesic, Parliament Speaker Vladimir Seks, War Veterans Minister Jadranka Kosor, Defence Minister Berislav Roncevic, a state secretary at the Interior Ministry, Ivica Buconjic, and representatives of town and county authorities and war veterans' associations.
The state delegation also attended a memorial service led by military ordinary Juraj Jezerinac, who said in his sermon, among other things, that the "causes of the aggression against Croatia in 1991 should be sought in the contempt for God and his commandments".
Jezerinac also criticised European politicians, saying that for four years they had not cared about the war-afflicted people of Croatia and Bosnia.
The bishop also said that the values of the 1990s Homeland War must never come into question.
Mesic and Sanader also saw an exhibition of wartime photographs, while Seks opened war veterans' sports games.
The state delegation later went to Okucani's soccer field to see a display of military and police exercises.
Operation Flash was launched on the morning of May 1, 1995 and was completed the next day. During the 31 hours, Croatian forces managed to retake 500 square kilometres of land from rebel Serb forces and regain control of the Zagreb-Lipovac highway.
About 7,200 Croatian soldiers and police officers were involved in the lightning offensive, 42 of whom were killed and 162 wounded.
The operation enabled the start of reconstruction of the Western Slavonia region and return of people displaced by war.
In retaliation for the defeat, Serb insurgents fired missiles with cluster munitions on Zagreb on May 2 and 3, 1995, killing six people and wounding 175, of whom 39 seriously.
The Hague-based International Criminal Tribunal for the former Yugoslavia (ICTY) later indicted Serb rebel leader Milan Martic for ordering the attacks.