China said it expelled a Dutch warship that entered its waters, a rare incident between the two navies that underscores tensions over contested boundaries in the South China Sea.China’s navy and air forces used “necessary measures including voice warnings and cautionary electronic interference” after the HNLMS De Ruyter frigate appeared off the Paracel islands and repeatedly launched a helicopter that violated Chinese airspace, according to a statement from the military on Wednesday.“China is resolutely opposed” to the Dutch behavior, the Southern Theater Command said, warning such encounters could “very easily cause misunderstandings and misjudgments.”The Dutch Ministry of Defence didn’t immediately…