By Krzysztof Bobinski
Crowds outside the presidential palace in Warsaw paid their respects lighting candles and laying flowers as news spread of the death on Saturday morning of President Lech Kaczynski and his wife in a plane crash in Smolensk, western Russia.
People throughout the country spontaneously hung out national flags decorated with black crepe as a sign of mourning after the unprecedented disaster.
The accident saw the death of many of the president' s senior staff, the entire command of Poland's armed forces, the head of the national bank, members of parliament and senior clergy.
They and relatives of some 4,000 interned Polish officers, who were murdered in Katyn in 1940 on the orders of the Stalin-led Politburo, had been flying to commemorate the 70th anniversary of the massacre in a wood outside Smolensk.
Another 18,000 interned Poles were killed elsewhere in the Soviet Union at the same time.
'Carving a role'
Poland's presidency is mainly ceremonial but the constitution gives the president responsibility for "representing" the country abroad.
Lech Kaczynski, who was elected president in 2005, used this right to carve out a role for himself in foreign policy.
He pursued an arms-length policy towards Russia. This saw as much attention being paid to defending Georgia's independence, and that of Ukraine, as a drive for better relations with Russia relations spearheaded by the government of Prime Minister Donald Tusk.
Lech Kaczynski had been president since 2005
Indeed, Mr Kaczynski often clashed with the prime minister. Earlier this week Mr Tusk travelled separately to Katyn to commemorate the anniversary with Russia's Prime Minister, Vladimir Putin.
On Saturday, Mr Kaczynski was to have celebrated the anniversary in the company of the Polish delegation alone.
The struggle between the two major parties in Polish politics was to have been resolved this autumn when a presidential election would have pitted Lech Kaczynski against Bronislaw Komorowski, speaker of the Polish parliament.
In accordance with the constitution, Mr Komorowski has stepped in to fulfil presidential functions. But he is clearly the favourite to win the election which now has to take place within 60 days of the tragedy.
Muted and overshadowed?
Lech Kaczynski leaves behind his twin brother Jaroslaw, who heads the right-wing, nationalist Law and Justice party and is a sworn foe of Mr Tusk and his more liberal Civic Platform movement.
Many Law and Justice MPs died in the crash and this leaves the way open for younger people in the movement and could see its reinvigoration.
The main effects of the crash may well come in Poland's relations with Russia.
The outpouring of grief at this unprecedented tragedy (Poland's only other president to have died a violent death was Gabriel Narutowicz who was shot by a deranged artist in 1922) is unlikely to translate into support for Law and Justice. Rather the election campaign will be muted and overshadowed by the memory of the plane crash.
The government now has to find new commanders for the armed forces which could, as in the case of the Law and Justice party, open the way to a new, more modern generation of military leaders.
Parliament will have to vote on a new central bank head in place of Slawomir Skrzypek, and replacements for other senior officials like the human rights ombudsman, Janusz Kochanowski, who also died in the crash.
The main effects of the crash may well come in Poland's relations with Russia. There is a danger that ingrained suspicion of Russia in Poland might colour the way the results of the official inquiry into the the accident might be received.
This will certainly happen if the inquiry is not transparent. The participation by Prime Minister Putin in the ceremonies earlier this week commemorating the Katyn massacre is seen by many as a major step forward in reconciliation.
It would be a supreme irony if the result of today's tragedy would be to deepen the mistrust engendered by the original Soviet massacre which Lech Kaczynski was flying to commemorate.
Krzysztof Bobinski is President of the Unia & Polska Foundation