What was the reason for the Dutch attack on Venezuela in 1908?

Question

The Netherlands attacked Venezuela in 1908, which resulted in the overthrow of Venezuelan President Cipriano Castro. According to the New York Times article Dutch at War with Venezuela, the Dutch said that attack was:

[...] a reprisal against Castro's government, which refuses to give satisfaction for his unfriendly acts toward Holland.

but did not explain what the "unfriendly acts" were. Wikipedia's Dutch–Venezuelan crisis of 1908 is slightly more detailed:

a dispute broke out [...] on the grounds of the harbouring of Jewish refugees from Coro in Curaçao.

But did not give references or citations on this statement, and did not explain who was harbouring the refugees, what they had to do with Venezuela and the Netherlands, and how this led to an attack and overthrow of a foreign government.

Answer 1

The reason was colonialism and trade rights. For this same reason, the Dutch had already sent a ship in 1902, along Britain, Germany and Italy.

In 1908, a second Venezuelan crisis occurred. Economic tensions with the United States escalated, in part from still unresolved issues involving the New York & Bermúdez Company. The gunboat Tacoma was sent to the Venezuelan port of La Guayra to put pressure on Castro. News of another planned insurgency, under a General Rolando, based in Trinidad, led Castro to strengthen his port defenses. In turn, British colonial authorities blocked Venezuelan ships from landing goods and passengers in Port of Spain, due to a supposed outbreak of bubonic plague in Venezuela. Castro then quarantined La Guayra, citing the same report of plague, and thus blocking British trade. Then Dutch authorities on Curacao began to restrict Venezuelan shipping. Castro retaliated with a virtual ban on foreign ships from conducting trade from Venezuelan ports.

By the summer, merchants on Curacao made a direct appeal to the Dutch queen, complaining the blockade was ruining the trade of Curacao, and with the somewhat ominous hint, that if the Dutch government did not take urgent action, the colony might invite the United States to establish a protectorate.

The Dutch sent a squadron of three vessels, Gelderland, Jacob van Heemskerck and Friesland, to the Caribbean and in early December 1908, established a blockade of the Venezuelan coast. Two small coasters were captured, Alix and 23 de Mayo, but on December 22, the Dutch government decided to lift the blockade.

Source: The Castro Crisis 1908: La Armada de Venezuela in GWAS

Answer 2

Just to add a little to explain the points in your question:

• what the "unfriendly acts" were:

In March it seems he seized a Dutch vessel carrying official correspondence from the Governor of Curacoa to the dependent island of Aruba. Intercepted the correspondence and imprisoned the crew and now he has handed his passports to M. de Reus the Dutch representative in Venezuela on the grounds that he is unfriendly medium!

The above from issue 67 of The Economist, published in July 1908.(emphasis mine)

This is also mentioned in the Book Gunboats, Corruption, and Claims: Foreign Intervention in Venezuela, 1899-1908 By Brian Stuart McBeth

Venezuelan gunboats continuously siezed many small craft that flew the Dutch flag, while many sailors from Curacao, just offshore from Venezuela, had been detained in mainland prisons.

• Concerning the Jewish refugees:

This conflict really started earlier, with the 1908 actions just really being the culmination. In 1902 the Jewish community in Curo, Venezuela requested aid from the Dutch government, since many had originally come from Curacoa:

Another outbreak against foreigners in June 1902 compelled the Jews again to seek an asylum in Curacao tendered to them by the governor of the island Jhr J 0 de Jong van Beck en Doom who upon learning the facts dispntched the Dutch man of war Koningin Regentesse to protect them. It returned to Curacao with eighty Jewish women and children on board In July following the same vessel was sent to La Vela de Core for the remainder and only a few Jewish residents remained

(from The Jewish Encyclopedia: A Descriptive Record of the History ..., Volume 4 edited by Isidore Singer, Cyrus Adler dated 1903)

More information on the Jewish settlement can be found in The Jews of Coro, Venezuela, by Isaac Samuel Emmanuel

I find no justification for the wikipedia reference to the refugees being the cause of the conflict, however.

Plenty of references exist from the time of these events, and most of the conflict seems to be based around corporate and national interests supporting various opponents of Cipriano Castro.